Understanding stone in relation to climate change | Conservation Day – Session 2

The Natural Stone Show 2023 | www.stoneshow.co.uk

Thursday 8 June – Conservation Day
In partnership with Historic England.

Session 2 –
Understanding stone in relation to climate change: a selection of current research projects.
With changing weather patterns, understanding the behaviour of stone and adapting approaches to its maintenance is essential. Researchers and stakeholders discuss a selection of projects which seek to address this.

00:00 – Introduction by chair Clara Willett, Senior Architectural Conservator – Historic England
02:52 – Climate change adaptations on the Commonwealth War Graves Commission estate including enzyme cleaning trials | Jon Gedling, Director of Works – Commonwealth War Graves Commission & Chris McLean, Senior Works Manager – Commonwealth War Graves Commission
30:37 – Understanding and measuring how stone properties influence biological growth | Dr Philip Skipper, Researcher – Lincoln University & Consultant – Philip Skipper Heritage Science Services & Dr Lynda Skipper, Senior Lecturer & Programme Leader – Lincoln University
1:01:00 – Treating organic growth using UVC light | Andrew More, Senior Building Services Engineer – Historic England
1:25:34 – Conserving the past, building the future: a collaborative approach | Michael Sheppard, Deputy Director – Cathedrals Workshop Fellowship (on behalf of the Institute of Conservation (Icon))

Well thank you we’re into our second session now uh so welcome it’s lovely to see you all um we’re really pleased we’ve got a bumper session for you uh I we have got uh gosh six speakers four presentations and the first three presentations are going to be all about climate change and adapting

Um looking after Stone and its maintenance so we’ve got some fantastic speakers we’ve got four presentations three of them are very focusing on uh research Innovation and then we’ve got a wonderful presentation about collaboration which is a really important aspect of conservation and stone so without further Ado I’m going

To introduce you to our first two speakers um we’re delighted to have the representatives from the Commonwealth wargraves commission um so we have John gedling um he is director of Estates and he’s responsible for overseeing the care and the upkeep of the Commonwealth wargraves uh estate um he’s a chartered building surveyor

He’s worked for the Royal household and for Eaton Eaton College um we’re delighted he is a member of the historic Estates conservation committee which is our esteemed colleagues at historic England and so he provides excellent conservation um advice and guidance for us and obviously for the Commonwealth wargrace

Commission so John will be talking first and then he’d be followed by um Chris Chris McLean is the Commonwealth War Grace commission um he’s the UK areas Works manager um they’ve both worked for the Commonwealth World Grace there’s quite some time um Chris manages a lot of the projects

That uh Commonwealth War Graves commission work on but we’re delighted to have such an important organization here um the Commonwealth War Grace commission honors the 1.7 million men and women of the Commonwealth forces who died in the first and second world wars and it’s got a global estate so it’s challenges are huge

And I think you’ll you’ll all recognize some of their estate from the little very small individual gravestones that we see right up to the massive cemeteries of feat fowl and the men in gate so they’re just a few of the vast estate that they have to look after so

They’re going to talk to us today about some of the challenges of conserving this huge and important and also diverse International estate and they’re going to talk about some of the ways that they’re approaching this so over to you John thank you very much okay thank you Clara well good afternoon everybody

Um so we’re going to talk a little bit first about about us and our estate just to give you a little bit of context and then some of the challenges we face and how we’re trying to address those challenges at looking after such a a sort of diverse estate at

Times of climate change we’ll also talk um about our use of enzymes to clean the stone which is very new for us um so first of all um you may be familiar as Clara says with our sort of lines of headstones in the cemeteries across the psalm or the posalian in Belgium

Um but we do really look after a very um wide range of memorials and cemeteries from dirt Valley in the center there which is lutchen’s memorial to the missing of the Somme uh to the men in gay on the top right in IPA in Belgium uh here in the UK the Portsmouth

Plymouth and Chatham um Naval memorials are shown on the center left picture and um some lesser-known but huge memorials such as along the bottom there that’s the Tao Chan Memorial in Myanmar um so just to give a sense of the scale uh 1.7 million War dead 150 countries and territories

Um every continent apart from Antarctica so from the commemorate War Dead from the Falklands right down at the bottom there uh up to um a cemetery in the Arctic Circle so a really huge spread the inset there shows Europe and you see that the by number of War dead commemorated France over 500

000 than Belgium and then here in the UK um so we’re funded by six member governments uh we have five operational areas and Regional Hub offices all around the world about 1 400 staff all together so what that means for us and looking after the estate well with 2 000 what we

Call constructed War cemeteries ranging from the enormous the largest of the mall which is time caught there on the left in Belgium um with with it the huge semicircular screen wall around about 35 000 names just on the screen were absolutely massive Cemetery uh um the um battlefields of passchendale to the

Smallest of them all on the right hand side there four casualties in Carolina in the USA tiny little Cemetery that’s cared for by our team in Ottawa in Canada uh here in the UK 300 000 War dead the length and breadth of the UK nearly every Parish church and Cemetery

Throughout Britain would have at least one uh War dead sometimes tens or even hundreds um in uh sometimes in plots sometimes dedicated cemeteries and sometimes just scattered around rural Church hours so example here up in uh up in the orkneys and some of the the features particularly associated with our

Cemeteries which you’ll see repeated all around the world so we’ve got the cross of sacrifice done by uh Reginald blumford four different sizes scaled according to the number of uh those commemorated in the cemetery uh with the bronze Crusader sword on one or both sides and then on the right hand side the

Great War stone or the stoner remembrance designed by Sir Edward luchens um fantastic design based on the principle of intarsis and none of the lines on it are are straight and ludgens designed one of those to go in every single cemetery and to be carved from a

Single block of stone and he was forced to compromise much to his disgust but that couldn’t possibly be afforded so now generally the cemeteries with a thousand burials is no hard and fast rule but that’s that’s the norm most of them are a single block of stone uh

Where that just wasn’t possible because of the logistics of bringing in a single block of stone in the 1920s they are in in pieces but most of them are single block of stone and the headstones then so we look after 1.1 million all around the world um particularly associated with with

Um Portland Stone and that’s probably the majority Stone type certainly in Europe but there are 25 different types of stone we’ve got slate some Sandstone um some Granite as well but it but it’s particularly Limestone and the choice really depended on what was available back at the time um and climatic and practical

Um decisions were made that that dictates the stone that was used but it’s interesting if you see all the cemeteries in northern France you’ll see a cemetery full of Portland headstones and one half a mile away with a different Stone type entirely quite often Hopton wood was used

And the the shapes 30 33 different shapes altogether the most common one of the the top left there but also the non-war Grays along the top the admiralty marker on the top right which predates the first world war entirely so we look after a number of those for the

Ministry of defense and along the bottom foreign Nationals each of whom would have a distinct headstone type and shape that repeats all over the world and we look after those on various reciprocal arrangements and on the right hand side there the German headstone design so lots of German casualties within our war

Cemeteries which we look after in exactly the same way as the Commonwealth Graves and we receive a grave rate from the German government to do so so some of the challenges then for us well I guess the most obvious is that the cemeteries by and large certainly

All the ones who most of the ones in Europe constructed in the early 1920s in the five ten years after the end of the first world war so the obvious challenges for us are dealing with uh stonework open to the elements for a century plentiful use of cement in all

The decades since unfortunately with all the problems that brings also some challenges about experimental use of materials such as bitumen um concrete mixes you know there were lots of techniques that were in there infancy in the 1920s and sometimes things have not stood the test of time unfortunately and tia Val which Chris

Will talk about in a moment there’s some interesting challenges of lots and lots of flat roofs and intricate network of internal downpipes and all the all the interesting issues that brings us um I guess in terms of uh just sort of setting the scene the the overall

Setting has changed so much for many of the the um War Cemetery so this is an example Taiwan in Hong Kong specifically designed to have that wonderful view down across the bay as shown on the left hand side there and on the right is how that looks now with the modern city

That’s developed all around so obviously we’ve got no control over that but the setting uh and the situation has has changed significantly um so as the first challenge can be one of geography so on the left hand side there is my colleague going to inspect the

Cemetery at the top of the Arctic Circle so that’s an old Russian ambulance that I think it was about a five-day trip to get up there um and on the bottom the cemetery you know man is either accessed by a boat or down those Cliffs so that posed some

Great challenges being able to care for these sites but also um sort of natural conditions so the the photo on the top right there is absolutely typical in Madras after the monsoon so that’s how it looks as to so many of the cemeteries uh in that in that part of the world and

That’s you know that’s just how it is there’s nothing we can do about it particularly but it but it poses a huge problem for our teams I’m caring for for the cemeteries um and flooding can cause very very expensive issues for us so this is uh Freetown Cemetery Sierra Leone where

Significant flooding across the land caused the sea wall to be pushed out to sea now shown on the photo of the right there so a project about five years ago rebuilding the sea wall um so we use system of gabians and we used to contract who was building the

Port did it for us but but you know huge issues in trying to implement a project like that remotely um and then the human effects um graffiti often not a huge problem but it can be it can be a very expensive problem that we that we have to deal

With that this is the top left Chatham Naval Memorial the theft of the part of the copper roof uh arson attack at the bottom left of cemetery in France sadly we we do see that and the photos in South Africa all that damage was caused by somebody trying to

Prize off the bronze sword um so we have many instances unfortunately the bronze swords had to be replaced with plastic including here in the UK where where we have no option you know on occasions and then with war and conflict sometimes means we can’t get to the cemetery at all so

Um we’ve got about 55 000 War dead commemorated in Iraq um a small number of the cemeteries have sadly looked to have been lost entirely but where we can go back in and reclaim a cemetery and it’s safe to do so we will and mosul is an example of that

Where we’ve just been able to go back and rebuild the wall and the United Nations had to clear the cemetery for us of um of uh mines so big project has just finished there and there are some successes along the way so we’ve got two cemeteries in Yemen and

A couple of months ago we got the first time back in there for five years so um that’s Marla where we’ve cleaned up and got the contractor back there but on a very limited scale so in terms of some practicalities I’m going to pass across to Chris and just

Talk a bit more about well how do we look after them and then um some of the new ways of doing so but Chris thank you good afternoon um I’m going to talk through a couple of the larger conservation projects we’ve worked on uh over the last uh last few

Years Chapel was a chapel Memorial to the missing Edwin Legends Memorial as John said flat roofs Legends loved his flat roofs and incorrect or just in inadequate drainage so we’ve got a lot of issues we’ve had issues with the chapel Memorial Tower Hill Memorial in

London uh so this was a project that we started back in 2014 a two-stage project we did the first first section uh leading up to the Centenary of the Great War so we did the first half of the memorial uh brickwork was replaced we like many other organizations we started

Using cement back in the 60s 70s and 80s uh the bricks were very soft bricks from Belgium they had about a four megapascal capacity we’re putting 30 30 megapascal concrete in there the bricks were failing so we essentially stripped out all of them order from the uh the bricks from the top half

Of the memorial uh uh a lot of the roofs had bitumen lined uh roofs on it so we restored it to its original condition uh as well as we could uh and then we did the second phase of this started about halfway through covid so again another huge challenge is working through covid

But we managed to get the second half of the memorial completed uh we did similar things but we also have about 72 000 names engraved on the panels on chat Val in the past we were quite uh quite uh we were quite quick to replace when things

Were starting to erode so we managed to we we only we anticipated we were going to replace about 130 140 panels we ended up doing about 30 and we re-engraved the ones that we could so we again were very much into not replacing where we where

We don’t have to any longer uh so the other project there we’ve just started that recently too so we started that back in April uh it’s a two-year project uh it’s probably about a five million pound value for the restoration of the memorial uh back in the 70s and 80s we

Coded the top of the memorial deal with the plastic sarnafill or the rubber membrane membrane’s good at keeping the water out until it gets inside so the water’s been trapped in there for years so the water has been saturating the stonework underneath so we’re stripping back the

Entire roof restoring it back to its original condition we’re also going to be trying and uh putting a bit of an Eco roof on there too so we’re going to be putting some Sedum mats on the top of it to try and uh try and bring some nature back to the

Site as well uh so that that Memorial uh it’s going to be a two-year project uh similar project to what we’re doing at chap Val uh replacing stonework were absolutely necessary but uh re-engraving the panels uh replacing Stone brickwork were required and the main thing is fixing up

The roof uh and this this funding uh quite a bit of this funding has actually been done with the the help of Flemish Heritage and the City of eper 2. so we’re not funding the the project ourselves 100 percent smaller projects so we’ve got uh we’ve got about 2 000 constructed sites around

The world uh we’re always working on some of our sites in each of the areas that we’re working in this is a nice small project that one of our Masons worked on at Liverpool Liverpool Naval Memorial it’s right on the sea front three meters not even three meters away

From the it’s completely saturated with salt water on a daily basis uh we have two Globes on there at Celestial Global natural Globe they were taken out in the 80s because they were corroding are eroding uh put botticino in Limestone slash marble it doesn’t age the same as Portland didn’t age very

Well so we took the decision about four or five years ago to reinstate the Portland so the the Mason that you see there is one of our stone masons he used to work for English Heritage uh he carved those two Globes himself over uh over a winter and we reinstated Portland

The two Globes are back as Portland uh again but we put them back in and after two years the salt water is getting into them again so we’re looking at methods of trying to slow the erosion of it so we’re going to be looking at lime washes

And uh to see if we can slow down the erosion of it but reinstate where we possibly can to the original materials I’m going to take that off so I can see most of our headstones are engraved at our headstone production facility in France uh John mentioned we have about

1.1 million headstones around the world uh our conservation-based approach we adopted this even before we officially adopted it back in 2013 2014 we were replacing about 25 26 000 headstones a year around the world most of it was Portland uh or most of the original headstones were Portland will be

Replacing them with other types of stone uh We’ve stopped that we’ve gone down to a more conservation-based approach we only replace one absolutely necessary in the past if there was some erosion starting to appear on The Headstone we were hiking at a perfectly good piece of

Stone and putting a brand new one back in don’t do that anymore uh we’ve got a new legibility criteria in so when we’re inspecting headstones there’s certain criteria people follow when they’re inspecting and we’re down now to about 1200 headstones a year we’re replacing so about a 96 97 drop in replacement

So many of the headstones are in constructed cemeteries but also in civil cemeteries uh in civil cemeteries and churchyards are in small plots so when we’re evaluating the headstones we look at the inscription uh using the guidelines the original the original guidelines those were set up in

1921. uh so we re-engrave where possible in France we have a full-time team working on it in Belgium we have a team also working on it uh so where we have the logistics are possible and we have the teams available we re-engrave uh and we do it year round so summer and winter

So you’ll see a little tent there they work on it keeps them out of the heat in the summer and it keeps them out and they put a little heater in there in the winter when they’re working and we engrave about 15 to 20 000 headstones a year in France and Belgium

So uh cleanliness now so this is a big issue for many organizations uh in the past the commission uh we we built a bit of a a rod we built a problem for ourselves we were cleaning everything super white every all of our sites were clean white headstones we were applying

Biosides we’re applying all sorts of chemicals to these headstones to keep them white uh many of these chemicals and biocides now are banned around the world and we were also putting chemicals into the soil so we we’ve we’ve we’ve had to move away from that

From a legal point of view but also from an environmental point of view we shouldn’t be putting chemicals in the ground we don’t need to so we we’ve come up with a new headstone cleanliness policy which applies to our structures and our headstones uh we don’t have any substantial change to the

Appearance of our headstones and fabric uh and but we also have to balance the effects of Aging so many of these structures are over 100 years old we were replacing Stone it was just not looking like a hundred-year-old Cemetery or 100 year old headstone so we have to

Balance the appearance but at the commemoration point of view so we have to commemorate the casualties adequately as well so now we don’t clean on an annual basis we were going in every six months to a year and putting biocides on all of our headstones in our big

Cemeteries we stopped doing that now we clean on an as needs basis our first step is using a nylon brush and water a lot of cemeteries a lot of headstones uh we that’s our first step but we’re also now we’ve John had mentioned earlier we are going down uh we are not trialing

Anymore we’re actually using enzymes so we started looking this about seven years ago and we’ve got enzymes that have been used in Belgium now for about three or four years and it’s now being rolled out to the entire commission so uh biocidal washes are no longer we’re

Phasing it out it’s almost phased out now we have some stocks which we’re getting rid of but we don’t use bio size as a rule anymore it’s cleaning with brush and water enzymes and as a last resort we do go uh from a logistics point of view it’s quite difficult uh we

Use thermatex and steam cleaning uh but that’s logistically hard in a lot of our sites and uh so we that’s our last resort but the norm right now is uh enzymes which we’re rolling out around the world so we’ve also and we’ve got a new sustainability plan that we and stated

In 2021 reducing uh reducing our Reliance on chemicals replacing stonework uh so we have a reputation for the high standards of care in our cemeteries we want to maintain that and we’re uh but we are now transitioning to a more sustainable method of conducting our work uh environmental concerns of our

Time right now are climate change and what loss of biodiversity uh both of these emerging Global Environmental disasters are results of humanities over consumption of Natural Resources so we want to minimize that so that’s why we’re replacing less stonework uh we’re going down the use of enzymes instead of

Chemicals into the ground we’re reducing pesticides and so we’re also we we’re using the use of volunteers we’re collecting data from around the world sites and properties to understand how we can adapt and modify our practices country by country as John mentioned we have 150 countries we

Operate in we have to adapt to the climate the current the availability of the materials and resources in these countries and what’s available so we have to work with what we have but we are minimizing the use of irrigation we’re looking at all of our use of resources minimizing what we can

And where we can without affecting the uh the sites themselves and that’s about it from me thank you both very much um I think you’ll agree that uh the scope of commonwealth law Grace commission the work they have to do and the way they have to adapt with the

Climate and with the resources we have while looking after the conservation of this you know highly significant estate um do we have some questions for the audience I think we’ve got time so thank you thanks um I don’t think I don’t think it’s a complex question but um

It’s probably a muggled question given what I have now just learned I’m old enough to have been taught by John Asher and I can remember him either giving a lecture or a seminar about the Viceroy house in India and whether the materials and more importantly the construction of the materials was

Appropriate for the climate of Delhi when the working details were based in London and then when I did my Master’s course down at Bournemouth with John on the Jurassic Coast we even went to the workshops at Weymouth college and carved our own headstone from Portland Stone

From the Isle of Portland now I’ve just learned from you that you didn’t say the stone has come from Belgium or France you just stated that the carving from your company or wherever is taking place in France all Belgium that’s my first question are you using Portland Stone from the Isle

Of Portland but what really interests me is and I’ll just use the example of your Hong Kong Cemetery were those Portland Stones slabs that had been sent out from Portland to Hong Kong and if they were and are given you’ve been explaining how you top up damaged Stone using local indigenous

Stone a subject that really interests me have you been measuring the weathering of the Portland Stone on the Isle of Hong Kong and how does it measure up to that same Portland Stone of 100 years that was shipped to Belgium for example and those are the kind of questions I

Met so I’m interested in weathering climate when you dispatched all these Stones scattered all over the world are you docking do you have a database of every headstone do you have a database of the maintenance of every headstone when you put enzymes on it and God knows

What five years ago 10 years ago 20 years ago lime cement Portland cement have you got a record of all this so you know what’s damage what’s gonna happen when in five years time I think there’s about 10 questions there yeah of course and yeah I’ll answer the question about uh

We use Portland Limestone so the the typical headstone we use is Portland Limestone we are sourcing our headstones from Portland still not from Belk no it’s Portland Limestone we do use locals local stones in France and Belgium for the for the crosses of sacrifice or the storm remembrance view

Is viewville uh we use massages so we do use French limestones in France if we’re replacing we replace like for like so your question was if if we’re replacing a headstone in Hong Kong we send a Portland headstone to Hong Kong erosion of headstones I’ve been to

Saiwan a couple of times uh they’re actually holding up quite well second World War Cemetery so they’re 40 or 30 years younger than the world war one we don’t replace a lot in in Hong Kong uh monitoring the erosion of headstones site by sight we don’t do that but we do

Have a database of uh replacement of headstones we’ve gone through a number of systems we’ve got one right now just about 15 years old so we can track back at least 15 years when a headstone’s been replaced and we have archives miles and miles of archives if we wanted to go

Into detail for an individual site yes if you haven’t got any more questions oh time for a quick one you uh do you recut the um existing stones and situ I mean it must be terribly difficult you know getting the accuracy if you’re just sitting on the ground

We have teams that dedicated teams so if we are re-engraving a headstone they have a template with them so a templates they have templates that they work on these they skim back the original surface so they spin it back not right back to the Bears not right back to the

Original like flat because we’d lose too much Stone the skim it back so then they can hand re-engrave but when when they re-engrave a headstone it looks like a brand new headstone once they’ve done it so yeah so it’s it’s done on site yeah yes it’s not an easy job because they’re

Also hunched over your memorials is that available to the public or is that something you use for your own Workforce and organization a lot of the guidance is now on our website so there’s quite a lot and our conservation policies for the organization are on the website as well

Now oh brilliant so that’s enough people can access all that read more that’s brilliant thank you both very much that’s fascinating to us so thank you very much [Applause] so we’re moving on now um to our next presentations next speakers we’re delighted to have Dr Linda Skipper and Dr Philip Skipper they

Are undertaking a research project which is funded by historic England understanding how the stone properties affect biological growth so doing a lot of work on this Dr Linda Skipper is a senior lecturer and program leader in the ba conservation of cultural heritage at Lincoln University she lectures on

Conservation as part of the degrees at Lincoln she is a experienced conservator on all sorts of materials from Stone historic wallpapers and pigments so she does a lot of analysis there’s a lot of teaching and a lot of research she’s she’s a phenomenal academic Dr Phillip Skipper is a fantastic microbiologist

With a wealth of experience we’re very pleased that he’s one of our consultants and he’s worked with us on several projects so we’re really Delight to have these two esteemed academics working on this fantastic project so they’re going to talk to you more about the concept of bioreceptivity and

Tell you about how they’ve been measuring it and working out methods for this process this is going to help us understand about selection of different Stone types because although they behave in their properties I thank you very much and thank you for that lovely introduction and for in

Giving us the opportunity to come and talk to you today about our research which as Clara said has been very kindly funded by historic England for this project um so what we’re going to talk about in this session is actually to cover the following aspect so I’ll start out by

Explaining the aims of the project and then I’ll explain that term that Clara mentioned as well bioreceptivity because it’s a term that we’re really interested in it’s the core aim of what we’re looking at and I know that some people might not be familiar with that concept

So I’ll work through what that is and why it’s significant in conservation of stone work then I’ll hand over to Philip who’s going to be talking about some of the ways in which we’ve measured virus activity he’ll sum up what we’ve found so far and then I’ll talk about what’s

Happening next because we’re not at the end of the project by any means we’ve finished the first phase but we’re now moving on into the second phase of our work so the aim of our project then is to develop a method which can become a standard for testing biological growth

On stonework and the problem at the moment is that there isn’t good data that’s comparable between different types of stones for biological growth and that’s what we’re very much been looking at so we’ve been testing and refining methods and we’ve used three types of stone initially as a proof of

Principle to show that the way that we’re looking at is is one that works so we’ve looked at a granite a limestone and a sandstone and we’ve looked at newly cut and we’ve looked at weathered surfaces and we’ll explain more about how we’ve done that um in a little while

So let’s start off then by explaining this term bioreceptivity and it was first defined in 1995 and it’s the measure of a level to which a material so not just Stone any material can maintain a permanent ecosystem of microorganisms so what’s really important here is it

Has to be a permanent Colony lots of surfaces will have transient microorganisms growing on it but they won’t um be a full colony in a permanent colony so obviously as we said in our case we’re looking at Stone but equally this applies to all sorts of different Heritage materials this broad bioreceptivity concept

So um really originally proposed that there were actually three stages of bioreceptivity and but much more recently in 2021 it’s been suggested that in fact there could be four stages and we could subdivide this further um but what wasn’t originally proposed in 1995 is a measure for bioreceptivity

Or at least one that can be used to compare between different studies unfortunately what that’s led to is that there are some groups who have attempted to measure bioreceptivity but most of these can’t actually be compared with each other so you can’t compare the results from one group with another

Because they’re not using the same methodology and that’s why going back to our aim we’re looking to try and work towards a more more standardized approach but it wasn’t until relatively recently in 2018 that Vasquez Neons group proposed a bioreceptivity index where a standard method could be used in

Compared granite and and then we’re starting to see some method of this more usable cross comparison and today that method has been picked up in a few studies but it’s mostly by people who were originally in that lab group and have moved elsewhere and it’s solely been looked at for granite and there’s

Very limited data for the UK before we go on to talking about how we’ve we’ve measured it what we’ve been doing I’m just going to run through the stages of bioreceptivity and what those are um so Stone colonization as I’m sure many of you know already is depending on

All sorts of different aspects it’s dependent on things including surface roughness and the availability of water and as the stone weathers you get changes in physical and geochemical characteristics that change the level of species that can be supported so the the amount of bioreceptivity as well as

Which species can be supported on that stone so the types of microorganisms that are growing um so there are ways in which this can be measured and primary bioreceptivity is defined as the initial potential for biological colonization of sound Stone and essentially gives a baseline reading for bioreceptivity studies

Then we have secondary bioreceptivity which is the potential for colonization of weathered Stone so it’s the kind of thing that you might for example see on monuments and gravestones but also plenty of Heritage buildings as well and and as I said before recently tertiary bioreceptivity which was post-conservation treatment has been

Proposed to be split into two different sections so the tertiary and quaternary um so Sam Martin has suggested that tertiary by receptivity is the measure of the level of growth on Stone but it’s been treated in a way that doesn’t leave a residue on the same surface

Um say for example laser cleaning or cleaning with water and then quaternary virus activity relates to a conservation treatment that um adds material to the surface so for example the use of a biocide that leaves some kind of residue on the surface and it’s always worth noting as well that potentially conservation treatments

That even though they fall under tertiary they might still modify the stone in some way and they modify the stone surface so for example steam cleaning can sometimes roughen the surface of the stone a bit and that can still have an impact on the the readings

So why are we interested in this in conservation well if we do look at lab based primary and secondary bioreceptivity it gives us information on how stains will weather in when we’re thinking about a biological patina so for example will a replacement Stone turn bright green and stick out like a

Sore thumb compared to an older weathered Stone and this also gives the basis to testing conservation treatments on sacrificial materials in a controlled fashion and that’s why doing some initial lab testing is very helpful because we can control all of these different variables if we were to do any kind of studies

Like this on a Heritage structure we’d very much be at the mercy of the elements we couldn’t control the light we couldn’t control the humidity we can’t control the temperature um and in the lab we can do that because we have equipment we can use climate chambers that very much

Um keep that controlled environment in place so that’s where primary comes in but in the literature today there isn’t really many studies that actually looked at secondary bioreceptivity at all and that’s on the weathered Stone and obviously to properly test the impact of conservation treatments you don’t just

Want to look at what happens on on a new freshly cut piece of stone you actually need to know what happens on weather today because that’s often the kind of material these treatments are going to be applied to so that means you also need a repeatable methodology for the secondary

Bioreceptivity and thinking about how you can test those treatments um so I think that’s the point where I’m going to be handing over to Philip so I’ll pass this one thank you all right so the studies in the literature are for the most part they’re very well planned

Stand-alone studies and they reflect the areas of the author’s interests well um but unfortunately as Linda mentioned earlier this has led to multiple methods being used uh using different types of microorganisms and different conditions so it’s actually really difficult to compare the results from say a study on

A Portuguese Limestone with a study on a French Limestone because the results that you get you can’t actually sit whether they have the same virus activity based on that and as we mentioned earlier as well one group has proposed a method for comparing bioreceptivity and granites but it

Hasn’t been widely adopted yet and the main message from these studies is that while these sorts of studies can provide useful information for Via receptivity a standardized method is clearly needed to be useful to the Heritage Community So based on our review of the literature we’ve developed what we’re hoping will

Become a standardized method for lab-based testing and this is based on the Vasquez Neons groups uh bioreceptivity index for granite um with just a mainly because it uses final measurements that a non-subjective and that they are repeatable and one way to one we’ve made a few changes one of which is to use

Commercially available species of microalgae because their group used a algal culture which they’d taken from Stone Surfaces in the part of the world they lived in um whereas we feel that if you can just contact a culture collection and get exactly the same thing each time this is beneficial

Um we don’t have time to go through the method here in detail here but in Brie the algae are placed on the stone and grown under optimized conditions to see the maximum level of growth that the stone can support the stone types that we’re using are three so two sedimentary

Stones and a granite so that’s Howley Park Sandstone which is uh the quarries around Leeds uh Jordan’s base bed Limestone which is a Portland stone and fogentor granite which is from the prison Quarry El Dartmoor which is now closed but it is still available through black and talk Granite they have sufficient supplies

So let’s start with our results from the primary virus activity we mentioned that they use that the methodology uses a couple of readings the first one is extracting chlorophyll from the algae that have grown on the surface and if we look at the primary bioreceptivity so this is the unweathered stone

All the stones having been inoculated with the same level of algal cells um we can see we wait took me weekly measurements until they’d reached a stable rate level and which was at two months and based on the chlorophyll a levels extracted the Jordan’s base bed unsurprisingly supports a higher level

Of growth than the Howley park or the fog and talk granite we also take colorimetry readings and as with the chlorophyll extraction the weekly readings were taken um but what we found compared to the original virus activity index for granite methodology was that the Howley Park Sandstone there

Was a non-biological driver to the color change so the environmental conditions in the chamber were resulting in color change in the stone and that the method for the granite doesn’t take in to account for this so we needed some way of controlling it and we’ll discuss that shortly

So but first we’ll talk about how you take these two readings and get a comparable measure um so Vasquez neon’s group in Spain proposed these calculations and they take the readings from the color imagery measurements and for the chlorophyll per centimeter squared it works out three level measures of bioreceptivity each of

Which is based on the scale of results in a output on a scale of one to ten the full description of how they arrived at the equations is in the paper which we’ve got in our reference section but basically they took they used the highest levels of growth that could

Occur on granite and worked out the equations from there in the paper they recommend that all three measures should be provided you have bioreceptivity index of growth which is based on the chlorophyll bioreceptivity index color which is based on the shift in color and then lab color space and

Then a final bar X activity index which is calculated from both and they’re consideration was that there may be issue times when things like the aesthetic impact is less important so you would look at either the total bioreceptibility index or the bioreceptivity index just from the growth

Or if you were wanting to integrate it into a facade then perhaps your main consideration would be the color change so going back to what we saw with the Howley Park sandstone um we’ve the other alteration we’ve made to their methodology is to include a algae free control to a account for natural

Color change in the Stone and in the case of Howley Park Sandstone the natural color change mentioned in the color imagery slide would have resulted in an artificial amplification in the bioreceptivity index and without as you can see if we hadn’t up the blue chart is without a control it’s

Um for the color change it’s almost quadrupled to the result so we really need to include this control it’s it’s not such a problem in granites because you don’t get the mineralogical shifts that would cause color change under the same conditions and are ongoing work which are placement student Robert is

Doing on limestones from along the Jurassic belt has shown that this isn’t just occurring in the Halley Park Granite it’s actually very common in British limestones as well so in the bioreceptivity index they propose the use of two increment divisions to provide a qualitative categorization of primary bioreceptivity

And from our data it appears that this scale is also applicable to secondary virus activity however as we build up data from different Stone types it might be that you’d need to revisit this because it could be that you get a large cluster of stones that

Are sort of between low and Mild virus activity so it might be that you’d want to actually split out this area a bit more um so having just said that it is applicable to secondary bar receptivity I will move on to that as we mentioned in the introduction

There have been very few lab-based studies looking at secondary barreceptivity and as studies need to be repeatable then we have to be we can’t just carry them out on Stone from the environment that’s been weathered because we won’t aren’t guaranteed to have different Stone types that have all been exposed

To the same conditions so once we’re adopting artificial weathering to give us our secondary bar receptivity and which allows us to test Stones which have been exposed to the same conditions using the same methods and the two main methods in the literature are thermal shock and salt weathering

However salt weathering can result in residual salts staying in the stone and that would impact on the bioreceptivity so we’ve chosen to go with thermal shock it’s based on the British standard for um determination of resistance to aging however the literature has shown that the times in the British standard are

Generous to say the least um so Studies have shown that an hour hot hour cold cycle results in exactly the same weathering as the British standard so that’s what we’re adopting so in brief we have one hour hot one hour cold but still for the same 20

Cycles that are in the British standard and from testing it with the three stone types which we then tested and compared changes in open porosity surface roughness and capillarity between the artificially weathered and the unweathered stone and statistical testing on the results showed that for all three stone types we had a

Statistically significant change in the Water absorbance by capillarity and the open porosity for the stones which tells us that our methodologies is causing genuine change to the stone this was backed up by petrographic analysis which was carried out by Dr Bradley staniforth of petrolab and he identified that there were changes to

The physical on position between the weathered and artificially weathered Stone um further demonstrating that the weathering process was successful and what you’d expect to see um also in the case of the Howley Park Sandstone very interestingly he identified mineralogical changes between the iron bearing minerals and we reckon

That this is the cause of the color shift that we’ve seen it during the testing so as the methods used to run the trials were identical between the weathered and unweathered Stone any variation in growth between them was due to the changes caused by the artificial weathering and we have again

Statistically significant differences between the measurements for each Stone type so as such we can be confident that the increase in bioreceptivity is due to this artificial weathering process there’s there are no other causes which could be impacting it and so this gives us a repeatable lab-based method for secondary bioreceptivity

So when we compare the calculated by receptivity index we can see that all three show a change between primary and secondary bioreceptivity and it’s only the Jordan’s base bed that moves between bat between the qualitative bands though so to summarize what we achieved so far we’ve defined and optimized a virus

Activity characterization method that’s repeatable and applicable to most Stone types we obviously haven’t tried everything yet and what we really want to do that now is to expand it to cover as many UK and international Stones as possible and the method’s also going to be suitable for lab-based testing of

Biocides prior to carrying out field trials so so the need for the small we use very small samples of stone for this so it makes it a lot easier to test what affects bar sides or treatments are having on the physical characteristics of the stone and whether the artificial

Aging of these biocides or treatments would have an impact which would result in accelerated deterioration of the stone Matrix and I’m going to hand back to Linda now to talk about our ongoing work okay so um obviously we’ve only tested three stones so far and that’s a yeah

It’s a great start but there are a lot more stones that we could test and we’ve actually moved on now to testing limestones that are currently available from quarries which are down the Jurassic belt and that’s um as Philip mentioned what our placement student Robert’s been working on and so that’s a

Project which you’ll finish around about the end of June in terms of categorizing thereby a receptivity and the final aim is that hopefully what would be really great would actually be to have an accessible database of the same properties of the bioreceptivity measurements that we’ve been able to

Find so that people have some kind of easy access to that so that you can make those cross comparisons when deciding what stone types are appropriate to use um the lab-based methodology that we’ve introduced not only gives us useful information about the bioreceptivity of stone types but as Philip said you’ve

Got this you’ve then developed this platform where we can reliably test conservation treatments such as biosize and consolidance on the bioreceptivity of the stone which is information that feeds into obviously the tertiary and quaternary bioreceptivity that I mentioned earlier so our study is now moving on to looking

At some of these alternative more sustainable biocides so that’s where we get our part of our link to the the climate change aspect of the session um and so we’re going to be looking at the impact of big nanoparticles essential oils a lime wash and also the enzyme Solution that’s used by the

Commonwealth wargraves commission which you’ve just heard about um and I should also say thank you very much to John because he very kindly provided us uh with the biomix enzyme solution for us to to test and we’ve also included algae clear Pro because that’s a fairly standard buyer

Side that people are using we tested that before and it seems reasonably effective and we want to use that as a chemical biasize so we can get a comparison between the other potential biocide types that we could use um we’re also going to use the system to

Be able to find out more about the impact on the stone itself and how biocide treatments might change the zone as that ages once we’ve used the lab-based technique to optimize biosi concentrations we’ll carry out a lab a field trial to then test these different biocides in the field

Um so we’ll hopefully maybe in a few years we’ll be back to tell you a bit more about that I think we’re pretty much out of time so I can’t say very much about our field trials just to say that we’re going to be doing those on Portland Limestone and

We’ve already started those growing their bacteria so we’ll be testing those a little bit later and we’ll take a range of different measurements to find out what’s happening to the stone including what it’s being colonized with so here are some useful references including many that we’ve mentioned on

The way through but I’m not going to linger on the slides I have one more that I would like to show you and it has a link to a short survey so what would be really helpful to us this next phase of our study is actually to find out

What people are doing now in terms of stone cleaning and whether you currently use biocides as part of your stone cleaning methods so if it works fingers crossed you should actually just be able to scan the QR code or if you wanted to take a photo of it you could obviously

Just type in that link and do that later we’ve also got our contact details up there I mean we’re here we’re happy to answer questions but you are also very welcome to email us later and thank you very much well thank you both very much for that and you’ve you’ve proven that your

Knowledge and expertise is why we got you to do this project um when I saw those sums and calculations on the screen I don’t know about you but I was like oh my goodness um but please we would love people to give us feedback we need that

Information to help inform uh the next phase of this exciting research um does anybody have any we’ve got time for some questions hi there um I’m a non-scientist so I really have no idea a lot of this is over my head but the one thing that I’m conscious of is

That when they’re talking about things like bio size and enzymes and so on and looking at it and testing it on Stone is one thing but what about the environment itself are these going to have an effect on the environment animals or the whole the whole you know biodiversity system

Well this is one of the reasons why we’re looking at things like the zinc nanoparticles the enzymes and essential oils is because they particularly the enzymes they will break down naturally the zinc nanoparticles will are bound to the surface so they don’t um transfer into the environment and

Essential oils have been used for well I really don’t know how long along with things like well we’re not going to use honey on Stone but honey is another good natural example of natural naturally occurring materials which have barcidal properties that have been used for a long time um

It is a it is a good good question it’s a major concern particularly because a lot of the buyer sides are currently in use are also in use in our hospitals so we really do want to move away from these because all we’re doing is driving biocide resistance in my in the

Environment which will eventually have health care impacts as well huh um I was curious and regardless of site the fixings of stone use of lime mortar Etc so and how does that affect the pH scale of the stone surface and it makes the biodiversity and does it affect it

In any way there’s going to be any documentation of that yes pH will affect the um virus activity and it’s one of the reasons why we’re actually looking at lime wash is because it will have a temp cause a temporary increase in the ph up

To around 10 or 11. uh what you do see though is that it will drop off fairly quickly it doesn’t last for more than a year or so there’s a lot of Coatings that are based around where the concept is based for inhibiting biological growth is based around the high alkalinity that they

Have and it even these ones which are commercially available they do drop off very quickly I think we’re getting yeah I think we’re going to have to move on with timings but um thank you both very much thank you thank you moving swiftly on our next speaker Andrew Moore

Um he’s a senior engineer at historic England with oh 40 years we’re really we’re really notching up some decades here um and he works obviously on historic buildings um but uh Andrew is going to talk to us about UVC treatment another alternative option for thinking about and treating

Biological growth on Stone so here’s one he’s prepared earlier which he’ll will have on the demonstration stand um I think also he’ll be showing it a bit later on the historic England stand as yeah essentially Andrew’s going to talk about the setup and the methodology for treating biological growth with UVC

Hello I’m Andrew Moore I’m going to tell you about the work that historic England has been undertaking along with some others in the use of UVC in the treatment of microorganisms growing on Stone and other similar hard surfaces armor Building Services engineer and all I know about stone is that it’s hard and

You can’t eat it so the first question that I need to answer is what is UVC it’s part of the um electromagnetic spectrum and the electromagnetic spectrum ranges from radio waves which have the lowest frequencies and thus the longest wavelengths through microwaves infrared the visible spectrum ultraviolet x-rays to gamma rays which

Have the shorter wavelengths and thus the highest frequencies so we’re all familiar with the visible spectrum and it’s what we mainly see and it runs from Red through orange yellow green blue and indigo to Violet and the illustration here shows the central colors of each color division

And there’s one or two people who can see just into the infrared in certain circumstances but not into the ultraviolet so if you’re wondering why infrared and UltraViolet the infra and infrared means lower frequencies than the visible spectrum and the ultra as in ultraviolet means higher frequencies than the visible spectrum

A quick equation the speed of light um which is constant equals the frequency which is usually measured in hertz or cycles per second times the wavelength normally measured in meters and so frequency and wavelength are inversely proportional as one goes up the L goes down now for sanity we’ll use the usual

Conventions in this sort of matter and we’ll only be making reference to the wavelength of ultraviolet light if we talk about frequencies you’ll get everyone will get hopelessly lost so the unit of measurement for ultraviolet light is nanometers and as you can see they are very small

And that’s about all you really need to know about nanometers so there’s three types of ultraviolet light UVA UVB and UVC and you can see the sort of wavelengths um limits at the bottom of the slide UVA has the longest wavelengths closest to the visible spectrum

Uvbs in the middle and UVC which is what we’re going to talk about in more detail as the shortest wavelengths and is closest to x-rays which give you a little bit of a clue as to what’s coming next so how is UVC or indeed ultraviolet light produced normally it’s produced by the sunlight

But a lot is filtered out in the atmosphere before it gets to us especially the UVC element and artificially the two current main ways producing ultraviolet light by various means of discharge or fluorescent lights or by Ed technology um holds seen on flash systems cold cathode lights also exist but you’re

Pretty unlikely to come across those and UVC lasers are starting to be experimented with and they may be very useful so a quick look at some ultraviolet lights um this is the underneath of a rig that my father who was a a lighting engineer and a keen philatelist built many many years ago

Um to detect the phosphorus on postage stamps they use The Fosters um to help sort the various postage rates um and so the dark lighter the dark sort of tube at the top uh that’s in black light blue and it’s made of woods glass and that filters everything to just a

Certain frequency 365 nanometers in the ultraviolet a range and there’ll be a discharge tube on the um that’s uh a UVC lamp and it does it looks as if it’s made of glass it’s not it’s made of quartz and again that that just emits UVC and

That Peaks at two five three point seven or sometimes two five four nanometers and I’ll come back to that in a second if you’ve ever been to an Old-Fashioned disco you will have seen the UV backlights glowing making fluorescent things work and so that’s what you see glowing in purple

The UVC light looks like this and if you see this you’re probably going to be in trouble fairly soon I only took this by putting in a huge slab of glass in front of the lamp and standing well back and got the camera to operate remotely

One of the other types of lamp that you will see floating about is the UVA bug zapper and that uses a slightly different type of black light shoe slightly wider Spectrum but again that Peaks at 365. and there’s one running in this demo rig down here which

I’ll tell you a bit about more more about in a minute now if you’re into LEDs most of you are familiar with the standard sort of um through the whole type of LED that almost anybody can solder up this is a rather fat one um and this um

Is some sort of black light I’m not quite sure what exactly the measurements are but it sort of glows quite happily and I can’t for the life remember why I bought them but one does so what does UV do and what’s it used for or the one you’ll all recognize and

You’ll see it glowing quite merrily down there is um making fluorescent materials fluoresce and you can see this more closely when you come up to our stand later and have a play around and the black light um uh used zapping lamps which is what this one is for safety that particularly is

Attractive to flies and other insects which is why it gets used UV has a well-known effect on the skin so this is UVA it ages the skin and UVB will will burn the Skin So hence the use of some screen products and you’ll see the A and UVB mentioned on them

We do need some exposure to UVB and small amounts to generate vitamin D and there are also certain uses of uh UVA and UVB and various wavelengths to treat certain medical conditions but we’re concentrating on UVC UVC is often referred to as germicidal because what it does is disrupts the DNA

Of organisms and kills them off and so it’s used for disinfection purposes and this is the quality that our research made use of um and this is guidance that uh Phillips the Dutch electronics company produced that specifies the various emissions of the different types of lamps and we used

The data in this for our calculations now if UVC kills things off you need some safety precautions and they can be really quite simple and you need them to stop the adverse effects as damaging the eyes or the skin so the simplest is to restrict the access

So don’t let the UVC shine onto your eyes don’t look at the light sources and lock the doors and that’s much easier to restrict access and the management than using complicated filters or goggles or protective skin wear and all the rest of it so what we’ve done on our experiments is

We simply locked the doors at night put some coverings over the glass operating some stuff on timers and all was well so now to the main part UVC can be used to clean off microorganisms growing on stock and similar hard surfaces and so it’s easier to shine UVC light microorganisms than it is

To try scrubbing things off with manual means um the microorganisms we’ve experimented with so far um are bacteria fungi and algae and also kill viruses although that’s somewhat outside of our scope and it will probably do terminally unpleasant things to lichens and mosses although we haven’t experimented on those yet

In passing I do have a fear that one day it will be proved that we’ve just exterminated the world’s only rare bacteria or Yeast or algae um entirely by accident but I’m told that’s not likely to be a problem but Murphy’s Law always seems to apply

So what it does is the UVC just upsets the DNA in everything that it shines on and it will wither away now in terms of people um it’ll burn your skin and it will irritate the eyes so that’s why you don’t want to do it but we’ve got enough

Protection that it won’t actually kill us but it is painful if you get uh UVC exposure so shining a light is a lot easier than manual cleaning so this may be an alternative to use in some circumstances so we’re going to tell tell you briefly about two examples that we got involved with

Um the first is about regular maintenance and that’s at the Newport Roman Villa on the Isle of Wight and the second is a one-off remedial work that we did at Fort brockhurst in gosport this is the Roman Villa at Newport well this is the building over the remains of

It the Roman villa didn’t actually look like that the remains of the Villa were discovered in the 1920s during some building works and it’s been a long a long story later it’s been covered over the forms small Museum and it’s operated by the Isle of Wight Council and it’s rather Jolly

Inside and if you’re on the Isle of Wight it’s well worth visiting um and inside there’s some Mosaic flaws and a hypercourse underfloor heating system served a sort of bath or Suite of bars or bathrooms and it’s thought that the high water table related to the nearby River Medina

And that’s called some dampness especially in the hypercore stand and to some extent on the um mosaics and that’s made life a bit difficult so we thought we’d start with something easy there’s Mosaic flaws um slightly easier to get to than the hyper Coast we built this rig or I built this

Rig it’s made out of Timber so it’s a standard size sheet of MDF with Timber edges bit of aluminum inside and some UVC lamps um and so we turn it upside down plonk it on the surface and away we go we uh we experimented with the help of

Some colleagues from the University of Portsmouth who identify the types of microorganism and the treatment times and this is the sort of results we’ve got so the areas down bottom left bottom right being treated the sort of slightly sad looking green mess in the middle is what it started as

So you can see it’s really quite impressive the second um rig we built was for the hyper coasts and so what I came up with it was a sort of suspended Timber version of the fourth Road Bridge the the suspension type thing um and here you can see the hypercourse

At the bottom with its little piles of stone that support the floor above and The Long Dark strips are some uh pieces of Timber with some reflective foil and then there’s battened fittings underneath and these uh here it’s using the original lamps that came with the

Buttons just to set the whole thing up um and here are some of the results that we got so on the left you can see the green build up of the material on the bottom of the hyper coast and on the right hand side you can see the effect

Um after a little while of running so it really did work extraordinarily well now the moral studio will realize that you’re not going to get all of the areas in the hyper Coast illuminated um adequately so we came up with a small box on legs um so you can get this into smaller

Areas and the first version used some meccano and the idea was that you can the uh the box with a lamp in it up and down to vary the exposure however Common Sense dictated that undoing all the nuts and moving things up and down and especially with the meccano was a

Real fast so we realized it was just easier to leave the thing jacked up at the maximum height move it around to suit and just vary the exposure time to all um so unfortunately the pandemic intervened at this point because the colleagues at the University of Portsmouth were going

To investigate of um UVC technology UVC LED technology but the Le UVC LEDs are the type that needs the special soldering techniques and they’ve got the lab set up with this and they were going to experiment with little tiny robot vehicles um similar to those little Robot vacuum

Cleaners and robot lawn mowers that some of you have either have or seen running around um but their idea was to use the very soft tires from slot cars or radio control vehicles so as to not damage the stone surface um but we haven’t pursued that and we’ll

Get going again on that at some point um in passing um the pandemic um you used a lot of UVC for sterilizing surfaces and somebody has come up with a com at least one person’s come up with a one concern has come up with an ex with

A rig that is about the size of the wheelbarrow devices the British army use for bomb disposal units they’re sort of they are literally about wheelbarrow sized with caterpillar tracks so if you can imagine one of those but slightly lower slung with a series of vertical UVC fluorescent tubes

And they use these in airports and I’ve saw one picture but it’s copyrighted so I couldn’t put it on the display at uh Heathrow Airport it just sits in the corner when the airport shut it trundles around um and does its thing so the idea of using something small to

Get into nooks and crannies um is is it will work um and also you can actually build UVC lights into the permanent lighting of an exhibition space if that was appropriate so that’s regular maintenance of keeping things obeyed to save archaeologists getting on their knees scrubbing at things with small brushes

Which is very painful on the knees so the second one I want to show you is for broadcast it’s a 19th century artillery Fort located in gosport the military got fed up with these sort of full back in the 50s and English Heritage ended up with it

And English Heritage now use their under license for ourselves in historic England and they store all sorts of strange and unusual stone archaeological artifacts Unfortunately they had two problems at the same time Murphy and his law struck they had a damp roof and a dehumidifier

Packed up so it all got very wet and mold decided to grow on the stones initially they were going to use hydrogen peroxide solution to clean everything now apart from the pong of hydrogen peroxide this year unpleasantness of it the cost of being astronomical and very time consuming plus it’s wet

So I carried out some calculations and realized that we could use UBC um explain what was what was needed and handed it the problem back to the English Heritage colleagues they engaged one of their electrical contractors who service that area and the Isle of Wight and built themselves a rig

Which looks like this so it’s a sort of um well I’m not quite sure what it is really it’s a sort of freestanding um frame there’s a name for these in your temporary if we’ve got forgotten what it is you have them in gardens um anyway in it they hung

UVC lamps wheeled the stones in locked the room up um and that was that was the treatment of the stones something like 30 odd tons and only one stone didn’t work and they realized they’d forgot to turn the thing over um and again they did a lot of experimenting in the type of

Microorganisms the time the time of exposure and it all worked well so this was part of their trial um and was quite expensive to build the rig they reckoned it was much more economical to do that there’s a one-off exercise than uh to try manually cleaning them so we’re preparing some written guidance

And it will probably look something like this and we hope to have that available later in the year or as soon as we can and that will explain those two um items are working much more detail so that’s coming so I’m nearing the end there’s the obligatory photographic credits which

You have no Great Value to you but you need to see them and I’m now happy to answer any questions um sort of over to you thank you very much Andrew so before everybody goes and rushes out and tries to build one of these things or tries to commission you yes what are

The limitations of this it sounds amazing and you’ve explained it very nicely to us as an alternative what are the limitations to using this well there is a modest amount of electricity used you’ve got to build the rig and you really I mean I built it because I’m a Building

Services engineer and I’ve been building things like this since I was a teenager um now you would probably ask an electrician or a lab technician somebody like that to build it for you um I think it’s a matter of experimenting so there may well be things where the UVC can’t reach

Um simply because of the stone structure it’s not really my field I just build the rigs and get on going so that’s that may be a concern and you may need to do some other cleaning methods as well as this but given that these are fairly

Simple to build and get going at modi’s Cost it’s probably better try something like this first assuming that you can make the space secure and and dark and see what happens yeah and then kind of go from there it’s still a bit experimental we know it works as you’ve seen

Um but each installation is different it’s it’s a tool in a conservators toolbox basically it’s a series of options so yeah that’s great do we have any questions how long do you have to expose the surface to UV seeds the first one we did we weren’t sure so we left it on

Overnight for a week um the lamps got too close to the surface and we managed to drive the surface out and get some Earth fluorescence now they’ve jacked that first rig I shown up on little legs and only use it overnight but when you do the calculations based on the data from

Phillips and others sometimes it will the UVC will zap things in seconds or minutes um generally speaking try it at a couple of hours first on a timer and see what happens basically um because common sense says the the least time you run the thing the less electricity you use although the

Electricity is modest the less we can use collectively the better if all else fails put it on a timer do it overnight and see what happens but you can get it down to quite tightly you can see the effect of it um you can read the effect immediately do fairly quickly yes

Um I think it takes a day or two for the things to actually die off I had left them to it to run and saw the results later um so I’m not quite sure how quickly it dies off but it for you to see the visible effects um but it is fairly quick

And indeed where they use the UVC in um labs and things like that where they have permanent installations business must work very quickly because they use them overnight and then when people are in the lab the lights are off so yeah it is so it kills quickly the visual effect

May be longer don’t know it’s the answer to that experiment soon let me know thanks Andrew that’s brilliant what I was going to say apart from a fantastic talk you’ve given us a lovely segue into our final talk which is really talking about collaboration so here we’ve seen our

Wonderful engineers and we talked about conservators and I’m delighted that we’ve our last speaker for this session is Michael Shepard he’s a conservator but also he’s a project manager and he’s worked in conservation for all his working life um Michael now is the deputy director of the cathedrals Workshop fellowship and

So yeah with at least 20 years experience um he and he’s managed many prominent conservation projects throughout the UK including the cathedral Lincoln Cathedrals West Front which I highly recommend you go and see now the scaffolding is down um so we’re delighted that Michael is coming to talk a little bit about the

Cathedral Workshop Fellowship but really he’s come to talk about the Institute of conservation’s camp pain about architectural architecture at Icon and really this collaborative approach between the disciplines so I’ll hand over to you Michael thank you hi uh good afternoon and welcome to this presentation on conserving the past

Building the future a collaborative approach today we will be discussing the importance of a collaborative approach in conservation architecture and historic built Fabric and our Focus will be on the interdisciplinarity of these fields and how they’re strongly interlinked with each profession bringing specific skills and trades to the table

We’ll explore how project professionals work in with architecture and built fabric can improve their chances of smooth project success by Consulting professional conservatives at early stages of project planning we’ll discuss how conservatives can support project professionals and introduce icon the professional body for conservation in the UK as a source of

Support and information and finally we’ll showcase the launch of the new headline architecture icon which underscores the importance of interdisciplinarity and collaboration between architecture and conservation so my name is Michael Shepard I’m an icon accredited conservator expert expertise in stone and decorative surfaces and I’ve got nearly 20 years experience both practically and

Managerially um I’m deputy director for the cathedral Workshop fellowship with the CWF where I’m responsible for organization development and managing funded projects which are predominantly our training levels currently between level two and level five the CWF was established in 2006 as a collaboration between 11 Anglican

Cathedrals and I do have to read this out because I always manage to miss one so that’s Canterbury Chester Durham Exeter Gloucester Lincoln Salisbury Westminster Abbey Winchester Worcester and yorkminster the purpose of the CWF is to establish a consistent and sustainable approach to developing specialized skills for the maintenance

And conservation of these cathedrals initially designed as a higher level training course for stone masons the foundation degree in applied historic building conservation and repair which is validated by the University of gloucestershire has expanded its offerings to now include Carpenters joiners electricians and plumbers but in the traditional sentences in lead workers

And since its launch in 2010 the program has successfully trained up to 52 craftspeople at level four and five and that’s with the assistance of our key funders who are specifically the Hamish oxen foundation and the worshipful company of Masons and what sets the CWF training program apart is the collaboration among these

11 Anglican Cathedrals drawing upon their expertise and talent these Cathedrals are iconic historical landmarks in England themselves housing numerous National Treasures and by uniting and designing this specialized training course the Craftsmen and women employed in these Cathedrals demonstrate their commitment to maintaining these invaluable Treasures the program’s success can be attributed

To the traditional Master to a to Apprentice approach where experienced crass people pass on their Knowledge and Skills to the Next Generation and the emphasis on workplace learning allows apprentices to gain practical experience and benefit from the guidance and support from their peers we firmly believe that the CWF that this

Approach is crucial by instilling in students the significance of working alongside conservation teams from the early stages of their careers and by fostering an interdisciplinary approach they become advocates for the preservation of historic buildings and ensuring the long-term security of our cultural heritage assets now architectural conservation design

And traditional trades are all closely linked in the field of cultural heritage management each profession brings a unique set of skills and knowledge to the table which when combined result in a successful and sustainable conservation projects for historic buildings and build fabric firstly let’s take a closer look at what conservation means

The primary aim of conservation is to preserve cultural heritage including historic buildings artworks and artifacts for future Generations and conservatives possess a deep understanding of the physical and chemical properties of cultural heritage materials and employ a range of scientific and Technical approaches to preserve and restore them they’re also well-versed in ethical and

Legal Frameworks that govern the conservation of cultural heritage architecture on the other hand is the Art and Science of Designing and constructing buildings Architects Structural Engineers and alike have a deep understanding of building materials techniques and Technologies and their skill that creating functional and aesthetically pleasing structures that meet the needs

Of their clients Architects play a crucial role in the conservation of historic buildings as they’re responsible for Designing and implementing alterations and additions to existing structures that preserve their historical integrity traditional trades Encompass a range of skills and techniques that they’ve developed and passed on down over generations and these trades oh sorry

These trades are a plenty including stone masonry carpentry joinery blacksmithing stained glass manufacturer lead working Roofing thatching and so many other skills that you can include very essential essential for the conservation of historic buildings traditional trades people have a deep understanding of materials and techniques used in historic construction

And a skill that using traditional tools and methods to carry out the repairs and restoration work now all three of these professions not excluding others obviously are successful to the essential for the successful completion of conservation on historic buildings and they create a nice circle of collaboration if you can all work

Together really well so conservances work closely with Architects and traditional trades people to ensure that conservation principles are incorporated into all aspects of a project from initial design stage to final implementation and Architects work with conservators and traditional trades people to develop conservation-friendly design solutions to preserve the historical Integrity of a building

Whilst also meeting the needs of their occupants and then finally traditional trades people look to conservators and to Architects to carry out those repairs and the restoration work with traditionally sympathetic techniques and materials which are often essential for maintaining a building’s historical authenticity so bringing together the different perspectives and knowledge bases which

Allows professionals to consider multiple factors and viewpoints when making decisions and by working together they can develop solutions that balance these competing priorities and this results in both a historically authentic and functional building for contemporary use so collaboration can lead to a more efficient and cost-effective project and conservation efforts and by involving

Multiple professions from the outset projects and professionals can identify potential challenges and develop solutions that consider the unique Technical and historical aspects of the project this can prevent causing mistakes and delays and it may arise if professionals work in isolation and Overlook important considerations a multi-disciplinary approach can lead

To a more sustainable conservation practice by considering the long-term implications of a project from multiple perspectives professionals can develop solutions that prioritize the use of sustainable materials and techniques and this can reduce the environmental impact on conservation efforts and ensure that cultural heritage is preserved in a way that is responsible and ethical

Conservatives play a vital role in this collaborative effort as they bring unique expertise and knowledge to the team drawing on scientific and historical research and technical analysis they develop conservation strategies that are both effective and sustainable and conservatives are trained to analyze and understand the materials and structures of historic buildings so that

They can develop conservation treatments that are tailored to the specific needs of each project we’ll like a chart of how a project runs don’t we so Consulting professional conservatives at the early stages of project planning is essential as it allows for a comprehensive understanding of the unique characteristics and challenges of

Any project enabling that successful outcome that we’re all looking for conservatives can conduct a detailed assessment of the condition of the building and identify any potential conservation issues they can also provide recommendations on appropriate conservation treatments and suggest ways in which to integrate modern technology and traditional techniques to achieve the desired

Results if at all possible so early conservation advice can help ensure that the conservation goals of the projects are aligned with its historical and cultural significance and by understanding this unique characteristic of each building conservatives can provide valuable insight into the history and cultural significance of the structure and develop conservation strategies to

Preserve its authenticity now possibly high up on the agenda commercially collaborative work with conservatives an early stage of project design can help manage costs and prevent delays we’ve all had those issues where we’ve encounters you know conversations with conservation officers and things have stagnated or got frustrated as

We’ve gone along the way and by identifying potential issues and developing effective Solutions conservatives can help prevent costly and time-consuming problems from arising later on in the project so how can icon help icon The Institute of conservation is a professional body for conservation in the UK and it serves as a valuable

Resource for those involved in historic building repair or conservation work and as a non-profit organization icon is committed to promoting high standards in conservation practice and providing support and information to a wide range of stakeholders including professionals and Heritage enthusiasts and one of the key ways in which icon is

Support that is involved in conservation is providing access to a network of conservatives who are both experienced and knowledgeable icon members are highly trained professionals who have undergone rigorous education and training in conservation of cultural heritage materials and they work as you can see here in a variety of fields including buildings

Architectural decoration paintings textiles meta work and archaeological objects and they can provide expert advice and guidance on a wide range of issues related to conservation icon manages a register of accredited conservators which lists professionals who have met a proficient standard of knowledge skills and ethical conduct and it requires them

To demonstrate their competence through a combination of academic qualifications practical experience and ongoing professional development the register is a valuable tool for those seeking to commission conservation work as it provides an assurance that the work will be carried out by a qualified and experienced professional working with accredited conservatives is

Crucial and if you want the work to be carried out by somebody who you know you can trust and it’s conserved in a way that not is only effective but also sustainable in the long term in addition to his network of conservatives icon also offers a wealth of resources and information on its

Website including guidance documents case studies and best practice guidelines and these resources are designed to help those involved in conservation work navigate the often complex and challenging process of caring for historic buildings and cultural heritage materials now whether you are a construction professional or a Heritage Enthusiast icon can provide valuable information

And support to help you make informed decisions about conservation work another important role that icon plays in promoting public awareness is the understanding of conservation issues and through its Outreach and education programs icon Works to raise awareness about the importance of conservation and promote the value of our cultural heritage for future Generations

And working with other key stakeholders such as the um Cathedral Workshop fellowship sbab and others icon is helping to ensure that conservation is high up on the agenda across various spheres of influence the new initiative architecture icon highlights the importance of interdisciplinary collaboration between architecture and conservation and aims

To promote a more integrated approach to the conservation of historic buildings icons realize that by fostering greater collaboration between professionals we can achieve more sustainable and successful conservation outcomes and the initiative recognizes that architecture and conservation are inextricably linked and that both professions thank you both professions bring unique expertise and skills

And through architecture icon they aim to provide a platform for Architects trade people and conservation professionals to share knowledge and best practice and to encourage more encourage more interdisciplinary learning and networking opportunities the initiative also aims to provide resources and training opportunities and to promote a more integrated approach to conservation and architecture

Icon have demonstrated they’re committed to supporting professionals across the conservation and architecture fields and they aim to do this re-architecture Icon by working together more effectively and more closely by promoting greater collaboration we can ensure that historic buildings are conserved to in a sustainable and holistic manner whilst also ensuring

That they meet and serve the needs of the communities that will use them for future generations to come yeah so I hope um you found this short presentation helpful and it’s highlighted The crucial role that collaboration between conservatives Architects and other pro project professionals by using ensuring a successful and sustainable conservation

Project with historic buildings early consultation with professional conservatives can help mitigate risks and ensure the best possible outcomes I encourage all attendees to learn more about icons over in the back corner over there um and ask people about his various resources and services including the new architecture icon initiative

And by all by all of us working together and utilizing these valuable resources we can continue to preserve and protect our cultural heritage for generations to come there’s plenty more to see and we’re over the hump of the uh of the day so I hope you enjoy the rest of your

Afternoon and thank you very much for your attention uh feel free to reach out to the icon stand um if you’ve got any further questions or you’d like to learn more thank you very much Michael um I think the collaboration is so important that you’ve mentioned between the different disciplines and

Conservation do we have any questions we’ve got a a short amount of time before the next session does anybody have any questions for Michael silence I like that I think some of this audience we’re we’re preaching to the converted because I imagine some of you are conservators a

Lot of you will be Architects or practitioners in the field so this hopefully will be music to to your ears I hope but um as you said we’d encourage you all to go over to the conservation area um to go and have a look at all the information we’ve got sbab

Um The Institute of historic building conservation as well as historic England and the English stone Forum but of course the Institute of conservation and uh they’ll be very very happy to talk to you more about uh conservation its broadest sense so thank you all thanks to all our speakers from this session

Thank you for attending and being such a great and enthusiastic and attentive audience um we’ll have the third and final session of the conservation conference this afternoon starting at two o’clock [Applause]