Is lime Render really the only choice?

Happy_Sloth

We have a 1860 Victorian townhouse, that has badly blown cement render and all the associated damp problems.   (Solid Brick, no cavity or damp course but also not listed or in a conservation area) 

A couple of years ago we looked at getting it re-rendered and ended up abandoning the entire thing because i couldn't get straight answers out of renderers and i tried to do some research on render only to discover half the internet seems to suggest that the only suitable option for a period home is lime.  

In the end we got someone from the heritage society to do a survey they said the cause of the damp problems what that the house had been inappropriately rendered in a cement based render.  Which while it appeared that the house has coped with the render for 40 years ... now the render had blown it was trapping water on the bricks.  They suggested that the only appropriate render for the house would be lime render. 

So we got a couple of quote and realised it was massively out of our budget.  We also learned that lime render needs lime washing every 5 years which means i'd need a couple of thousand pounds to rent scaffold every 5 years not to mention the cost of the labour and wash it's self.  

Roll on a couple of years, the damp problems are getting worse.  We've recently inherited some money so I'm revisiting the render situation because it's getting quiet grim.  

We've had a quote for Lime and the price went up significantly from last time and it's still out of our budget and I'm still concerned about the long term costs of maintaining Lime as it's a big house and scaffold for it costs a fortune.  I've been quoted £4000 for scaffolding just to get my facias and soffits done.  

So i got some other renderers in to look at it,  just to see if i could get a more affordable option. So we've been told that some of the newer renders are vapor breathable and should be ok .... and here i am spinning again. 

i can't find any solid advice on the internet about putting modern render on an old single brick home that doesn't say "DONT" .... So i don't know if the renderers are simply clueless or just trying to get my money?  There are a lot of Victorian houses in the UK, I live in an area with lots and I suspect many of them don't have lime render. 

Anyway one renderer who suggested one of the modern renders, suggested i rang the manufacturer and asked them for their opinion.  So i rang the two main manufacturers the renders people have been suggesting. 

I've now had 2 manufacturers of modern silicone render tell me that they have a render that will be fine on my home.  One of which sent out a surveyor and has offered me a 10 year guarantee assuming the renderer follows the specification they provide. 

Surely the manufacturer wouldn't suggest it, if it wasn't ok? there website has pictures of rendered homes, some of which are clearly a similar age to mine.  If the house has survived the last 50 years with cement render surely a modern breathable render would be 100 times better even if it wasn't quite perfect? 

But if you google, the internet just says it's a bad idea.. 

Now i don't know what to do? i really can't afford the lime, im not in a conservation area and my house is not listed.  

Any ideas? 

FreeBear

Personally, I am very skeptical about the claims of silicone renders being breathable - The same goes for the majority of masonry paints t hat make the same claim.. Way too much hyperbole and very little in the way of hard data.

Whilst lime renders benefit from a lime wash coating every five years, you don't have to do it so often. Nor do you have to accept a basic white finish - Like silicone renders, pigments can be mixed in to a lime render to give you a self coloured coating.

Have a chat with someone like Mike Wye about lime renders and how they might compare to the alternatives.

theoretica

I wonder what the cement manufacturers were claiming 40/50 years ago?

Was it originally rendered or brick? Removing the render but not replacing it is another option to consider, maybe.

FreeBear

theoretica said: Was it originally rendered or brick? Removing the render but not replacing it is another option to consider, maybe.

Problem with not replacing the render is brick damage. Bricks will get chipped and gouged removing the existing render, and they may well be spalling unseen. One way to keep the costs down is to chip off the render yourself - Get a couple of cheap air hammer/chisels from ebay, a decent compressor, and some long hose. I appreciate finances are stretched to breaking point, but the tools can be resold once the job is done. If you decide to do the removal work yourself, make sure to wear goggles & dust mask. Be very careful around the windows (get one of the boys to hold a sheet of plywood over the glass if needs be).

justwhat

What is under the current render?
Many people remove the render as often it is not original. Then just repoint.

i assume its a sandstone rubble wall. 

GSDMum

Can you not patch the bad 'bits', perhaps a professional would be able hide any seams?

https://www.lime.org.uk/community/faqs/i-have-cracks-in-my-lime-plasterrender-how-do-i-fill-these.html

Rosa_Damascena

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.

Happy_Sloth

FreeBear said:

theoretica said: Was it originally rendered or brick? Removing the render but not replacing it is another option to consider, maybe.

Problem with not replacing the render is brick damage. Bricks will get chipped and gouged removing the existing render, and they may well be spalling unseen. One way to keep the costs down is to chip off the render yourself - Get a couple of cheap air hammer/chisels from ebay, a decent compressor, and some long hose. I appreciate finances are stretched to breaking point, but the tools can be resold once the job is done. If you decide to do the removal work yourself, make sure to wear goggles & dust mask. Be very careful around the windows (get one of the boys to hold a sheet of plywood over the glass if needs be).

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. 

Happy_Sloth

justwhat said:

What is under the current render?
Many people remove the render as often it is not original. Then just repoint.

i assume its a sandstone rubble wall. 

Its a double brick wall,  it's not sandstone.  we have considered removing it but in the areas we checked the brick appears to be in a bad condition

Happy_Sloth

theoretica said:

I wonder what the cement manufacturers were claiming 40/50 years ago?

Was it originally rendered or brick? Removing the render but not replacing it is another option to consider, maybe.

The house originally have lime render we believe, we have a photo of it from the 1920's and the house appears to look (white or light coloured)  so it hasn't been left as bare brick at any point during it's life as far as we can tell. 

Happy_Sloth

GSDMum said:

Can you not patch the bad 'bits', perhaps a professional would be able hide any seams?

https://www.lime.org.uk/community/faqs/i-have-cracks-in-my-lime-plasterrender-how-do-i-fill-these.html

The issue with damp is caused by inappropriate Cement render, it all needs to come off patching isn't an option.