re: breathable "exterior" paint for lime rendered cottage?

[chippy1]

Hi,

Please could someone give me a little advise on a good exterior paint that is durable, long lasting and breathable for a 300yr old cottage that has lime plaster walls.

A previous owner has used a Farrow & Ball water based exterior masonry paint which has been on for many years but still in very good condition, no bubbling or flaking so would be almost impossible to remove, so need something that can be applied directly on top of the old paint.

Would a silicate based paint be the best option? I understand limewash is the cheapest option to use but needs alot of maintenance every 2 or 3 years so was looking for something as a more long term option.


Would really appreciate any help or if anyone could recommend a product I could try.

I have found a couple of options but have had no experience with either so would appreciate any help.

https://www.keim.com/en-gb/mineral-products/keim-exterior-paints/soldalit/

OR

http://www.limestuff.co.uk/breathable-paints-limewash/mapei-silancolor-exterior-paint/

Many thanks

 

[paulc]

Welcome aboard. I see you took the advice over on MSE to join in here (No, I'm not a stalker).

I would normally advocate lime wash on lime render, but with the (suspect) prior use of F&B along with the desire for a long lasting finish, a silicate paint may well be the best option. I'm sure others will be along over the next few days to pass comment.

Don't expect an instant reply, as many of the regulars only pop in a few times each week.

 

[chippy1]

Welcome aboard. I see you took the advice over on MSE to join in here (No, I'm not a stalker).

I would normally advocate lime wash on lime render, but with the (suspect) prior use of F&B along with the desire for a long lasting finish, a silicate paint may well be the best option. I'm sure others will be along over the next few days to pass comment.

Don't expect an instant reply, as many of the regulars only pop in a few times each week.

Hi paulc,

Thanks for your reply.

Yes, some very helpful members over at MSE pointed me in this direction! told me this is where the experts hang out! New to this sort of thing, so could do with all the help I can get!

I have read that I could first use a special "primer" that would help bond the silicate paint to the pre-painted lime plastered walls but with so many options, you end up just going round in circles!

Thanks again.

 

[worms]

Yes, welcome across here! There are several of us who visit both sites (and get frustrated by the poor advice that is often given on MSE for people with queries about older homes!)

 

[88v8]

Limewah creeps into cracks, and so acts as a sort of running maintenance. It's a DIY job, interval will depend on exposure. Two years upwards.

Silicate paints are primarily for permanent surfaces such as stone. They can be used over sound renders that do not move, but I wouldn't use them on wattle panels.

The F&B could be stripped off using Peelaway, but if it's well bonded there's no need. Of course that raises the question, what's under the F&B.......... It would be irritating to spend £200 on silicate paint then find it fails.

What's under the lime render? Stone? Wattle?

Ivor

 

[chippy1]

Limewah creeps into cracks, and so acts as a sort of running maintenance. It's a DIY job, interval will depend on exposure. Two years upwards.

Silicate paints are primarily for permanent surfaces such as stone. They can be used over sound renders that do not move, but I wouldn't use them on wattle panels.

The F&B could be stripped off using Peelaway, but if it's well bonded there's no need. Of course that raises the question, what's under the F&B.......... It would be irritating to spend £200 on silicate paint then find it fails.

What's under the lime render? Stone? Wattle?

Ivor

Hi Ivor,

Thanks for your message.

To your question.....What's under the lime render? Stone? Wattle?

Even that isnt an easy one to answer....strictly speaking, I would have to say all of the above. The outer shell is lime plaster/render but as the property has been extended over the last 300 years and a number of materials have been used (stone/wattle/brick) The paint work has bonded well throughout the property so its about finding something that will "keep" it in good condition and help protect the property for another 15-20years....Is there a "one size fits all" type of paint that would work?

Companies like KEIM seem to suggest they have paints suitable, that can bond with mineral substrates but also bond to existing paint coatings?

https://www.keim.com/en-gb/mineral-products/keim-exterior-paints/soldalit/

KEIM Soldalit is a highly developed multi purpose exterior sol silicate paint system based on a combination of KEIM potassium silicate and silica sol binding agents, forming a chemical bond to mineral substrates and a mechanical bond to existing paint coatings.

KEIM Soldalit is ideal for application onto both previously painted and mineral substrates, combining the benefits of a classic mineral paint with simplicity of application.


http://www.limestuff.co.uk/breathable-paints-limewash/mapei-silancolor-exterior-paint/

Silancolor is a silicone resin based paint that has the advantage of traditional mineral based paints as well as synthetic paints. Thanks to Silancolor paint's special formula, it leaves the substrate permeable to water vapour and considerably water repellent.

Use on surfaces where very high water repellence and excellent vapour-permeability is required for the substrate.
Can be used on all cement or lime based renders.
Can be painted over existing paint.
Requires an initial coat of SILANCOLOR PRIMER

My experience with these products is less than 0% so happy to get any advice I can from the experts on here!

thanks again

 

[Tc345]

Following advice on here we've just painted the front of our house with Seciltek silicate paint from Mike Wye. One coat of primer, two of the paint and while it took a while due to the surface area we had to cover it was very easy to work with. Our house is ~200 years old brick construction with a render on the front (likely a bit of a mix but largely lime). 5+ years ago it was limewashed and so was looking very, very scruffy and made all the scruffier by washing it down to remove any loose limewash and other muck. But that just made the contrast post-painting all the more pleasing!

The paint is not cheap, £400+ for us, but if it lasts as long as it's supposed to it'll be well worth the investment. Ivor's point is one that we didnt need to consider but that depends on your home's construction.

 

[chippy1]

Following advice on here we've just painted the front of our house with Seciltek silicate paint from Mike Wye. One coat of primer, two of the paint and while it took a while due to the surface area we had to cover it was very easy to work with. Our house is ~200 years old brick construction with a render on the front (likely a bit of a mix but largely lime). 5+ years ago it was limewashed and so was looking very, very scruffy and made all the scruffier by washing it down to remove any loose limewash and other muck. But that just made the contrast post-painting all the more pleasing!

The paint is not cheap, £400+ for us, but if it lasts as long as it's supposed to it'll be well worth the investment. Ivor's point is one that we didnt need to consider but that depends on your home's construction.

Thanks Tc345!

Funny you mentioned this as just had an e-mail reply from Mike Wye recommending this:

https://www.mikewye.co.uk/product/seciltek-silicate-paint-sp-01/

and a primer
https://www.mikewye.co.uk/product/seciltek-silicate-primer-ad-25/

I'm just waiting for confirmation whether this can be directly applied over the top of a water based exterior masonry paint. Did you have any issues putting it on over the pre painted walls?

Thankyou again.

 

[Roger440]

Following advice on here we've just painted the front of our house with Seciltek silicate paint from Mike Wye. One coat of primer, two of the paint and while it took a while due to the surface area we had to cover it was very easy to work with. Our house is ~200 years old brick construction with a render on the front (likely a bit of a mix but largely lime). 5+ years ago it was limewashed and so was looking very, very scruffy and made all the scruffier by washing it down to remove any loose limewash and other muck. But that just made the contrast post-painting all the more pleasing!

The paint is not cheap, £400+ for us, but if it lasts as long as it's supposed to it'll be well worth the investment. Ivor's point is one that we didnt need to consider but that depends on your home's construction.

I too was pondering this over the weekend having spied this paint on Mike Wyes website. Sadly, mines been painted with a modern paint and there are also some cement repairs. Not quite sure how to get the old paint off yet :?:

Good to hear you are pleased with it.

 

[chippy1]

Thanks again for all the help on this thread...really appreciate it!

One more question! Please could anyone confirm what is an "acceptable" level for breathable paint on old proeprties?

After doing a little investigation I found out a number of different paints have been used over the past 20-30years, (before I purchased the property) so unless I'm going to take everything off and lime render from fresh, its just about finding the best option to go over what has already been applied. It would also seem some of the property was extended in the 60s and brick/cement render was used, maybe thats a big reason why the lack of lime wash hasnt been a big issue with previous owners.

The current paint which was applied 5years ago has bonded well and no flaking and have found out that Farrow and Ball do a breathable exterior paint that has a Sd value of 0.118 and is given a class 1 rating. It's been mentioned that anything lower than 0.14 is rated as Class 1. Not the best option but is this breathability rating acceptable for a house that needs to breath? (until I can afford to re-render in the future)

thank you again all...

 

[paulc]

After doing a little investigation I found out a number of different paints have been used over the past 20-30years, (before I purchased the property) so unless I'm going to take everything off and lime render from fresh,

For removing paint, I've resorted to grit blasting in the past. Probably a bit too extreme for a lime render.. Depending on how much acreage of walls you have to do, perhaps a carborundum stone would be an effective method of removal. One such as this - https://www.flooringtoolsdirect.com/carborundom-stone-with-handle

Various grades of grits are available from very coarse to fairly fine. If the paint doesn't clog up the stone, I'd imagine it would be quite effective.

 

[88v8]

Paint removal, Peelaway or Klingstrip.
Or more easily, plastic media blasting http://www.blast-cleaning.co.uk/index.php?menuid=50&component=content&task=article&articleid=39&categoryid=9.

There is really no point in spending a lot of money on 'breathable' paint. (breathable is a slippery word) if the underlayers are non-breathable.
Just do what is necessary for maintenance or aesthetics, and leave breathability until you can strip off back to lime.

For cement, any old paint really. You can't smother cement, it's already dead.

Another option, is Pozilime. http://www.ingilby.co.uk/pozilime.html yet another of these long-life breathable paints. Though how linseed - an ingredient - can be regarded as 'breathable' beats me.

Ivor

 

[Flyfisher]

‘Breathable’ is indeed a slippery word.

Here’s an interesting discussion of what it means in practice: http://cornishlime.co.uk/information/breathable-paints-explained/

 

[chippy1]

Paint removal, Peelaway or Klingstrip.
Or more easily, plastic media blasting http://www.blast-cleaning.co.uk/index.php?menuid=50&component=content&task=article&articleid=39&categoryid=9.

There is really no point in spending a lot of money on 'breathable' paint. (breathable is a slippery word) if the underlayers are non-breathable.
Just do what is necessary for maintenance or aesthetics, and leave breathability until you can strip off back to lime.

For cement, any old paint really. You can't smother cement, it's already dead.

Another option, is Pozilime. http://www.ingilby.co.uk/pozilime.html yet another of these long-life breathable paints. Though how linseed - an ingredient - can be regarded as 'breathable' beats me.

Ivor

Thanks Ivor!

As I've been working through this process I've come to the conclusion that whatever I put on the exterior will only be as "breathable" as the most "breathable" underlayer of paint and over the last 50+ years there has been many different types of paints used. The current layer of paint is Farrow and Ball, a "breathable" masonry paint with a Sd value of just over 0.1. I could go out and spend £300-£400 on a breathable paint with a sd value of 0.05 but the underlayer will always restrict the breathability to that 0.1.

As the underlayer has bonded well and no dampness it would seem the "safest" option to stick with the same paint to go over it....The plaster is in excellent condition, so removing layers and taking it back to the lime plaster seems like a big job when at present no repairs are needed.

Thanks for your comments Ivor, I was willing to spend hundreds to get the "right" paint but you make a excellent point that I'll always be restricted by the underlayers so spending a lot of money on the "best" doesnt seem the wisest move at this point.

thankyou

 

[Tc345]

Following advice on here we've just painted the front of our house with Seciltek silicate paint from Mike Wye. One coat of primer, two of the paint and while it took a while due to the surface area we had to cover it was very easy to work with. Our house is ~200 years old brick construction with a render on the front (likely a bit of a mix but largely lime). 5+ years ago it was limewashed and so was looking very, very scruffy and made all the scruffier by washing it down to remove any loose limewash and other muck. But that just made the contrast post-painting all the more pleasing!

The paint is not cheap, £400+ for us, but if it lasts as long as it's supposed to it'll be well worth the investment. Ivor's point is one that we didnt need to consider but that depends on your home's construction.

Thanks Tc345!

Funny you mentioned this as just had an e-mail reply from Mike Wye recommending this:

https://www.mikewye.co.uk/product/seciltek-silicate-paint-sp-01/

and a primer
https://www.mikewye.co.uk/product/seciltek-silicate-primer-ad-25/

I'm just waiting for confirmation whether this can be directly applied over the top of a water based exterior masonry paint. Did you have any issues putting it on over the pre painted walls?

Thankyou again.

Ours was painted over old limewash and we had no problems with application. I washed the walls with a stiff brush to remove the worst of a the loose stuff, anything more than that and the render itself was brushing off too. Whether it stays put for the claimed 20ish years, we shall see. When I queried this with Mike Wye they didnt seem to thin it would be an issue and that it would be fine to paint over existing paint. The info on the website supports this.

 

[chippy1]

Following advice on here we've just painted the front of our house with Seciltek silicate paint from Mike Wye. One coat of primer, two of the paint and while it took a while due to the surface area we had to cover it was very easy to work with. Our house is ~200 years old brick construction with a render on the front (likely a bit of a mix but largely lime). 5+ years ago it was limewashed and so was looking very, very scruffy and made all the scruffier by washing it down to remove any loose limewash and other muck. But that just made the contrast post-painting all the more pleasing!

The paint is not cheap, £400+ for us, but if it lasts as long as it's supposed to it'll be well worth the investment. Ivor's point is one that we didnt need to consider but that depends on your home's construction.

Thanks Tc345!

Funny you mentioned this as just had an e-mail reply from Mike Wye recommending this:

https://www.mikewye.co.uk/product/seciltek-silicate-paint-sp-01/

and a primer
https://www.mikewye.co.uk/product/seciltek-silicate-primer-ad-25/

I'm just waiting for confirmation whether this can be directly applied over the top of a water based exterior masonry paint. Did you have any issues putting it on over the pre painted walls?

Thankyou again.

Ours was painted over old limewash and we had no problems with application. I washed the walls with a stiff brush to remove the worst of a the loose stuff, anything more than that and the render itself was brushing off too. Whether it stays put for the claimed 20ish years, we shall see. When I queried this with Mike Wye they didnt seem to thin it would be an issue and that it would be fine to paint over existing paint. The info on the website supports this.

Thanks Tc345...

Mike Wye did get back in touch and said as a number of different paints have been applied over the years to the exterior walls, they felt I would need to break up the existing paint by sanding down the walls before using this paint. So it came down to using "MAPEI SILANCOLOR EXTERIOR PAINT" or the current paint (Farrow and Ball). As the F&B masonry paint has bonded well, it seems like I should just stick with what I know until I re-plaster in the future. Limestuff (website) told me the Mapei silancolor would not adhere to limewash but is ok to put directly over old paint but as Ivor mentioned earlier in thread, not much point spending alot of money on the "best" paint/limewash etc unless I was looking to remove all the old paint and strip back to the lime plaster, only then I could really benefit from using some of these "specialist" paints. The paintwork/plaster of the property is still in good condition and paint has been on for 5years, so stripping it all back seems a big expense when its not currently needed. So in the meantime i might just have to go with the F&B breathable masonry paint and start saving!

 

[chippy1]

Paint removal, Peelaway or Klingstrip.
Or more easily, plastic media blasting http://www.blast-cleaning.co.uk/index.php?menuid=50&component=content&task=article&articleid=39&categoryid=9.

There is really no point in spending a lot of money on 'breathable' paint. (breathable is a slippery word) if the underlayers are non-breathable.
Just do what is necessary for maintenance or aesthetics, and leave breathability until you can strip off back to lime.

For cement, any old paint really. You can't smother cement, it's already dead.

Another option, is Pozilime. http://www.ingilby.co.uk/pozilime.html yet another of these long-life breathable paints. Though how linseed - an ingredient - can be regarded as 'breathable' beats me.

Ivor

linseed?...I recently had someone treat my front door (which is the original door from when house was built) and they used linseed oil to treat the wood....at the end of the job the workman left a rolled up cloth (that had been used to treat the door) in my hall, over the next few hours the linseed started to smoulder and I came home with a porch/livingroom full of smoke...as I opened the front door, the cloth went up in flames. Luckily all ended fine and I was able to remove the cloth in time but the workman and myself found out that day, that Linseed is a risk of spontaneous combustion, without a need for an external source of ignition, if not stored correctly....Lets just say, I've not allowed linseed or the workman back in my home since!

 

[Cubist]

Paint removal, Peelaway or Klingstrip.
Or more easily, plastic media blasting http://www.blast-cleaning.co.uk/index.php?menuid=50&component=content&task=article&articleid=39&categoryid=9.

There is really no point in spending a lot of money on 'breathable' paint. (breathable is a slippery word) if the underlayers are non-breathable.
Just do what is necessary for maintenance or aesthetics, and leave breathability until you can strip off back to lime.

For cement, any old paint really. You can't smother cement, it's already dead.

Another option, is Pozilime. http://www.ingilby.co.uk/pozilime.html yet another of these long-life breathable paints. Though how linseed - an ingredient - can be regarded as 'breathable' beats me.

Ivor

linseed?...I recently had someone treat my front door (which is the original door from when house was built) and they used linseed oil to treat the wood....at the end of the job the workman left a rolled up cloth (that had been used to treat the door) in my hall, over the next few hours the linseed started to smoulder and I came home with a porch/livingroom full of smoke...as I opened the front door, the cloth went up in flames. Luckily all ended fine and I was able to remove the cloth in time but the workman and myself found out that day, that Linseed is a risk of spontaneous combustion, without a need for an external source of ignition, if not stored correctly....Lets just say, I've not allowed linseed or the workman back in my home since!

Glad to hear you caught it in time Ivor and glad to hear that the workman concerned is not allowed back. This risk with Linseed Oil is well known, particularly in the furniture manufacture and restoration business. Its best to make a practice of burning any used rags or cloths, irrespective of what oil is used, asap.

 

[malcolm]

Glad to hear you caught it in time Ivor and glad to hear that the workman concerned is not allowed back. This risk with Linseed Oil is well known, particularly in the furniture manufacture and restoration business. Its best to make a practice of burning any used rags or cloths, irrespective of what oil is used, asap.

Out of interest how do you make your windows last for 200 yeaes now? It is widely known that soaked rags need to be put in a bucket of water.

 

[Cubist]

Out of interest how do you make your windows last for 200 yeaes now?/quote]

The glass is not so much of a problem but the frames are - "you can't get the wood you know" - copyright S Milligan.