Exterior limewash problems

[JoceAndChris]

Hello hope all are well!

Busy year here having a complete re roof and new lead. Ouch. Could have bought another house here for the cost of that!!!! Still, it's looking good, and needed doing. Will upload some piccies.

I'm now attempting to touch up exterior limewash where there are patches of damp damage from the leaking guttering. But, my touch up has caused giant blistering and the limewash to lift entirely from the lime plaster beneath. Any ideas what to do? Also, the patched in limewash looks amazingly patchy - will I need to completely repaint?

Thanks, Joce

 

[Flyfisher]

Welcome back Joce

Sounds like you've been having an exciting year with the roof, I imagine it looks fabulous.

I've been doing lots of limewashing this year but have never experienced the 'blistering' you describe, even on exposed flint. Do you know what limewash formulation was previously used? I'm making my own from matured lime putty with no additives but I know that some premixed limewash contains tallow. Where this has been used it can sometimes be more difficult to get fresh limewash to 'stick' without fairly vigorous brushing.

As for the patchiness this could be because it hasn't yet fully carbonated or, more likely I'd guess, is simply too thin. I'm finding it necessary to use three coatings on new areas before I get uniform coverage. I also tend to finely spray each coat in the evening of the weather is warm.

Having said that, I'm just using plain white limewash and I recall you had a coloured limewash? I've no experience of this but I've read that it's very difficult to exactly match coloured limewash so that patching is quite difficult. Perhaps that' she problem?

 

[plasticpigeon]

Hello Joce, lovely to hear from you!! I'm looking forward to pictures one the roof is done. Are you also having the lead over the entrance replaced? I don't know the answer to your problem, but my experience with other types of paint is that if it is put on thickly, problems can arise as the outer surface dries and shrinks more quickly than the wet paint underneath. Could it be that the limewash you are putting on is a bit thick and could do with being watered down?

 

[JoceAndChris]

Really useful thoughts there - thanks FF and PP! Will certainly try three thin coats and use mist in between and see if that helps. I did give the limewash a really good stir and the consistency seemed fine, but the colour seemed darker. It's been stored in a garage ( hasn't frozen) for two years- It's "Naples" by Rose of Jericho which is a warm ochre.I'll give them a ring and see if they have any ideas.

When I asked the lads who originally did the limewashing ( who've been back here this summer for lime plastering and lime washing of our 4 chimneys) whether or not I could patch in limewash they looked a bit dubious and said it may or may not work.

I'd sooner live with it less than perfect than completely repaint just yet, I think.

Great you two have been busy from what I read! 8)

PP- yes - all new lead in the gutters and the porch and dormer. Roof is completely finished now (50 k in total :shock: ) and the chimneys finished - and the leadwork - and also we have completely restored all sashes using draught proofing, new locks, and new paint, and new pulleys! The house is finished on the outside except I'd like to change the porch doors still!

 

[livias]

Limewash patching will never look perfect but there are ways to minimise the patchiness. Unless you are using pure white don't try to feather it out, that will not look good. Edges look least jarring if they are short and probably straight following the lines of the building, so for example you could limewash up to the side of a window and then finish with tidy straight line which runs up above and down below from the edge of the window. One of the reasons that combed parget panels were so popular is that they break up the wall surface and provide numerous suitable places to make tidy daywork joints of limewash or lime plaster

Lovely roof. It looks so much better

 

[JoceAndChris]

Thanks livias. Love pargetting - it looks so fantastic. Less fancy, but I had the house scored to resemble ashlar blocks when it was lime plastered 2 years ago. I'll remember your tip about painting up to the edge of the block and see if I can make that work where the damage is only minimal.
This bit though, we are talking long streaks of rainwater damage that's now looking like long streaks of differently coloured limewash.
I think I'll need to repaint the whole front facade.

This is the "blistered" bit I've now picked off - but there are other bits where the limewash is no longer adhered to the lime plaster beneath.

 

[88v8]

How annoying.
The colour... the sun will have bleached it.

Poor adhesion the SPAB say https://www.spab.org.uk/advice/technical-qas/technical-qa-18-limewash/ 'Reasons for poor adhesion can be preparation with ordinary bagged lime, coats being applied excessively thickly, inadequate dampening down before limewashing, or too rapid drying out.'

Limewash typically requires renewing every five years. Suitable surfaces are brushed down and minor mould growth removed with fungicide. They are then dampened (normally with a hand-pumped spray) and limewash is applied thinly and worked in well, using a large, rough-textured brush. At least three or four coats are usually needed, each preceding coat being allowed to dry and the surface dampened down before the next goes on.

I presume they are referring to something like a Killaspray, rather than a hand mister.

As with many things traditional, one can understand why it was superseded by simpler albeit inferior materials.

Ivor

 

[noj]

That limewash looks very thick to me - how many coats were added originally?

Where I've applied five coats (internally) it's still nowhere near as thick as that appears in the photo - maybe why it's lifting off?

 

[JoceAndChris]

That limewash looks very thick to me - how many coats were added originally?

Where I've applied five coats (internally) it's still nowhere near as thick as that appears in the photo - maybe why it's lifting off?

4 coat work. I think it probably doesn't help! But I think why it's lifting off in spots is because moisture has got between the lime render and the limewash - it's only the damp affected areas where this has happened, and it's worst where it's had both guttering dribbles and prevailing winds and weather.

How annoying.
The colour... the sun will have bleached it.

Poor adhesion the SPAB say https://www.spab.org.uk/advice/technical-qas/technical-qa-18-limewash/ 'Reasons for poor adhesion can be preparation with ordinary bagged lime, coats being applied excessively thickly, inadequate dampening down before limewashing, or too rapid drying out.'

Limewash typically requires renewing every five years. Suitable surfaces are brushed down and minor mould growth removed with fungicide. They are then dampened (normally with a hand-pumped spray) and limewash is applied thinly and worked in well, using a large, rough-textured brush. At least three or four coats are usually needed, each preceding coat being allowed to dry and the surface dampened down before the next goes on.

I presume they are referring to something like a Killaspray, rather than a hand mister.

As with many things traditional, one can understand why it was superseded by simpler albeit inferior materials.

Ivor

That's really useful - thanks Ivor. In another three years I'll certainly be happy to tackle the whole thing, for now I'll just have to put up with it a bit blotchy I think!

 

[MikeG]

Are you really sure that the render is lime? It looks rather like sand/ cement render to me, in which case some problems with limewash wouldn't be unexpected.

 

[plasticpigeon]

Are you really sure that the render is lime? It looks rather like sand/ cement render to me, in which case some problems with limewash wouldn't be unexpected.

MikeG, get to the back of the class. It is very brave man that dares to suggest that Joce may have employed anyone but the best firm using the best materials.

 

[MikeG]

:lol:

I should read all of the thread first before commenting, I guess. I hadn't appreciated that it was lime render applied by/ for the poster. (Still, it looks an odd colour to me........).

 

[Flyfisher]

4 coat work. I think it probably doesn't help! But I think why it's lifting off in spots is because moisture has got between the lime render and the limewash - it's only the damp affected areas where this has happened, and it's worst where it's had both guttering dribbles and prevailing winds and weather.

If you haven't done so already, it might be worth contacting the company that did the rendering and limewashing for their comments.

We had the front of our house completely stripped and re-rendered/limewashed in 2014 and a small section of the render showed signs of failing last year and became quite obvious over last winter. I sent photos to the company that did the work and they immediately sent out someone to have a look. Without prompting they agreed there was a problem and said they would repair it when the 'lime season' came around. In June this year, they stripped back the failed render (and more, to ensure the 'join' with the existing area would be invisible), re-rendered and re-limewashed the entire area and it's back to looking pristine again. Can't really fault that level of customer service.

 

[JoceAndChris]

just catching up with this! Fab service there FF - lovely to get it repaired.

I'm in an interesting position with the company who did the lime plastering ( which, yes, was carried out by rather famous plasterer :lol: ) This company are one of the few in the UK you would contact if you had a crumbling Grade 1 monument, and they are taking me on as an employee. I will be accompanying the MD on site visits and writing up the very lengthy documents he prepares on church monuments and what the course of action is for their care and repair. Not just churches - for example this company have just carried out the meticulous restoration of the sphinxes in Crystal Palace.

So yes, they will be hearing about my limewash problems, but not just yet. I also need them back for quite a lot of interior lime plastering.


In any case, the failure of the limewash is nothing to do with their work and everything to do with a very leaky guttering system.

 

[JoceAndChris]

:lol:

I should read all of the thread first before commenting, I guess. I hadn't appreciated that it was lime render applied by/ for the poster. (Still, it looks an odd colour to me........).

It was more biscuity when it was done, but most definitely lime

This was after stripping off the very thick cement render

And after the second coat of plaster

And then working on the ashlar blocks

It was an incredible labour of love to get the crisp sharp lines the architecture requires. It's a cottage, but needing a formal treatment.

 

[steveb]

I kind of agree with Ivor here - I love the idea of traditional limewash, but can see why it is rarely uses any more.

I used silicate paint on the outside of my place - breathable and lasts more or less forever (it's still old technology, I wouldn't go near "modern paint" )

-Steve

 

[JoceAndChris]

I kind of agree with Ivor here - I love the idea of traditional limewash, but can see why it is rarely uses any more.

I used silicate paint on the outside of my place - breathable and lasts more or less forever (it's still old technology, I wouldn't go near "modern paint" )

-Steve

I'd be interested to see piccies Steve!

I know my limewash finish isn't looking its best in the photo I posted on page 1, but overall, with crumblage, it's still a very beautiful and romantic aesthetic. It weathers in a patchy, mottled Italian villa type of way. I do love it. The lack of uniformity is both its strength and weakness.

Here's another, also looking beautiful in its dilapidated state.

And again, would be sorted out by a proper repaint if the guttering and roof are ok.

 

[steveb]

yes, the paint is a pretty uniform finish although it does darken and lighten with moisture so looks much better when it has rained and is drying out, it has that lovely blotchy patina for a while but in summer it goes pretty much solid colour.

Here's the only pic I can find from here - it's rather less grand than yours being an old farm workers cottage. There are a number of non-period details and I don't like the plastic gutter/downpipes, but not disliked enough to replace them since they are functional

http://goo.gl/photos/88TaSTRJSFGGzzdk9

The colour is "sandstone" Earthborn silicate , one primer then 2 coats. Hopefully last 100 years

 

[JoceAndChris]

I think that looks lovely! A very nice period looking finish!

Will let you know whether I'll switch to Earthborn silicate after living with the limewash 10 years or so! :lol: