Is lime Render really the only choice?

Happy_Sloth

Rosa_Damascena said:

A heritage society will never recommend that you slap on the most modern material with gay abandon. Lime render is definitely not the only choice, but if you are going to do this properly it cannot be on a budget.

Get existing render stripped off, a damp course introduced, insulation pads if required and a silicone / monocouche render applied. It will last for decades without maintenance but will run into several thousands.

Even for modern render we are looking at 20-30k which we do just about have, but the quotes for lime at 40k +.  We inherited some money so we can get together the money for modern but it's is a once in a lifetime spend, 

i simply can't afford to get it wrong.  If i spend 20-30k and its wrong and all needs to come off again I'm in serious trouble. 

stuart45

Happy_Sloth said:

i simply can't afford to get it wrong.  If i spend 20-30k and its wrong and all needs to come off again I'm in serious trouble. 

That's the important issue. The problem with makers claims of of breathability is they that don't really say exactly how breathable they are. Even sand/cement renders and mortars allow a certain amount of air to pass through them, but nowhere near as much as lime render/mortar. Again different types of lime are better than others.
Are the damp problems on one flank or all round the house? Are the inside walls lime plaster?

twopenny

What about having a chat with a National Trust Estate Office?

I remember that all the cottages here had been given a modern render back in the 70's and they were having to take the whole lot off and learn to make and replace with lime render because of damp problems which also caused decay. It was very interesting.

Many of the cottages on Exmoor have to have this.

I had a discussion with the Holnicote Estate Office at Selworthy on Exmoor where they mix the lime render. They had to learn from scratch.

https://selworthy.cylex-uk.co.uk/company/the-national-trust-23757178.html

Maybe a call and if you can make a personal visit that may be better. There may be one nearer to you. You want to talk to the people acturally duing the work or in charge of it.

They'll be able to give an unbiased point of view which may save you some money or at least help you feel secure in the decision you make.

Happy_Sloth

stuart45 said:

Happy_Sloth said:

i simply can't afford to get it wrong.  If i spend 20-30k and its wrong and all needs to come off again I'm in serious trouble. 

That's the important issue. The problem with makers claims of of breathability is they that don't really say exactly how breathable they are. Even sand/cement renders and mortars allow a certain amount of air to pass through them, but nowhere near as much as lime render/mortar. Again different types of lime are better than others.
Are the damp problems on one flank or all round the house? Are the inside walls lime plaster?

You see this is where i'm trying to rationalise it ...... 

it's semi detached the only wall that is badly blown is the gable end,  that is granted 75% of our entire wall space as it's a narrow deep house.   

The gable walls are the only place we have any damp problems and if you look on the outside of the house you can see cracks in the render where the damp issues are and if you tap the render on the gable it's all very hollow sounding. 

in my head (Maybe i'm reaching) if i don't have damp issues where the render is intact and cement render is the worst type possible. Then surely getting anything better is going to be OK? 

All our damp problems appear to be caused by water getting in, not water getting out as far as we can tell. It's an old house air circulates well and there is plenty of ventilation. 

To add to this ... all the Plaster inside the house appears to be modern plaster (Mostly done in the 80's judging by the wall paper) we have been living her for 3 years and we haven't got to internal decoration yet.   All the internal plaster is also in a bad condition, we had the electrics done and every time the electrician tried to create a gully for the wires we lost half a wall down the to brick.  So it's easy to see what sort of plaster we have.  Even the Hall which we suspect hasn't been decorated since the 60's appears to be plastered in cement.  

I know that if i commit to lime render on the outside, i need to commit to lime plaster on the inside otherwise it's all more or less pointless.  After all putting a string vest on a over the top of man wearing a bin bag isn't really going to stop him sweating. 

Lime plastering like lime render seems to be a specialist trade and that starts a whole other ball rolling about what to do about breathable paint, wallpaper etc. 

The age of my property is not that unusual in the UK, so im just really surprised that this seems to be such a difficult topic.


 

FreeBear

Happy_Sloth said: This is a very big house it's a bigger job than we could tackle, we are being quoted weeks for the removal of the render from teams of specialists. 

From one of your other threads, a 3 storey town house, so I can see why scaffolding costs are high. Regardless of which type of render you use, over half the labour costs are going to be in the removal of the cement render. This is not a high skill job, just time consuming and messy hence the suggestion to rope in family to get it off.

To add to this ... all the Plaster inside the house appears to be modern plaster

I know that if i commit to lime render on the outside, i need to commit to lime plaster on the inside otherwise it's all more or less pointless.  After all putting a string vest on a over the top of man wearing a bin bag isn't really going to stop him sweating. 

Contrary to what many people say, modern gypsum plasters do allow moisture to pass through, so don't get too hung up on breathability and must have lime plaster internally. The problem with gypsum plasters is that the stuff is water soluble, so if the stuff gets damp repeatedly, it turns to a powdery mush. Lime plasters and renders on the other hand, will tolerate damp - To a certain extent, any damp will help to heal micro-cracks by leaching calcium carbonate out and depositing it on the surface as the moisture evaporates. If you have ever looked at the formation of stalactites/ stalagmites in a limestone cave, it is exactly the same process.

Might be worth your while posting over on the Period Property Forum - A very useful resource of information, and a very helpful bunch. Depending on the area, they may be able to put you in contact with tradesmen that don't charge the earth.

TELLIT01

Is it possible to breakdown the work and get the worst wall(s) done first?  'Weather' tends to predominantly come from one direction so that wall should be priority.

Mickey666

Firstly, the cement render really needs to come off.  This will likely be an easy, though messy, job.  Damaging the underlying brickwork is likely to be inevitable because of the damage caused by years of trapped damp, but it will only be the surface layers (spalling) and not a structural issue.  Once re-rendered, no one will ever know.

As for lime render, I've never really understood why builderschrge so much for it.  I suspect that most are frightened off by it.  But someone who knows what they are doing should be able to do the job for not a great deal more than cement render.

As for limewashing, that's not the only option adn the OP should investigate silicate paint.  This is genuinely as breathable as limewash but should last for 20-25 years.  There is lots of information on line, or speak to some heritage specialists, eg: https://www.mikewye.co.uk/product/seciltek-silicate-paint-sp-01/

It is more expensive than limewash (which is cheap as chips, cheaper than most masonry paints) but its longevity is its advantage, expecially if scaffolding is necessary. 

On the scaffolding subject, would a cherry picker be an option?  Hire costs would be around £250 per week so far cheaper than scaffolding, if access is not an issue.

As for limewashing . . . I was once quoted a little over £13k to limewash half my house, including scaffolding, by a 'conservation specialist' building firm.  I subsequently found someone who would do it from a ladder for £90/day (I was providing the limewash), but he was very vague about how long it would take for three coats.

A building company will almost always quote for scaffolding because of H&S considerations, whereas a self-employed tradesman can make their own decision about working from a ladder.

In the end, my son did it for me from a ladder and it took him less than one week for three coats all over and a fourth coat in a few places.  Four years on and 90% of it remains in perfect condition and the few areas that need patching will take me about half a day using a ladder.

stuart45

You could also have a look on the plasterers forum. You need to avoid something like this.
2.5 years old lime render crumbling away... advice appreciated | The Original Plasterers Forum - The Plastering Forum - A forum For Plastering - Rendering Forum

Alfster

Is the render really that badly blown over the entire property? If you tap on blown render with a hammer it makes a hollow sound. What percentage is blown? Have all the renderers said it all must come off. Can you upload some photos? I have a 200 year old cottage and part of our house is rendered in cement. We had some damp issues. I hacked off the delaminated bit and repaired it. I did the same on the inside but let the inside dry out with the plaster off for several months. If all of it is in that bad a state why not try hacking some off and seeing what it's like underneath? I can always been cleaned up and repointed in lime mortar if the bricks haven't all spalled. If some if bad but most is ok you could always remove the render then paint it in a breathable paint as an option such as Keim or Emperor paint.