When to remove render

[Easrow]

Good afternoon everyone.
This is my 1st thread on here...have to start somewhere.
I read through here quite alot for pointers and to just be nosey really.
Me and my girlfriend have bought a detached brick and rendered house in somerset built in 1847. There are numerous issues and problems which we knew about and are happy to deal with. There is one thing I can find very little about and that is when to remove the outside render. It's done in concrete and on one wall is pretty much all hollow. We have many damp issues for many reasons so obviously need to dry it out. The brickwork behind the render is soaking and makes a clay instead of dust when drilling into it and wallpaper is coming off left right and centre with dark patches appearing on the walls.
Is it a good idea to remove the render now it's winter or will it make little difference? The plan is to get it re rendered in lime at some point. What are people's thoughts/experiences.

 

[JoceAndChris]

If it's that saturated in my view it's going to make little difference when. We chopped off sections and had it bare years. You could remove it now and pin up hessian sheeting just to protect your wall a bit. Not sure if you've read the other cement render thread, but test patches and sucking before you see are important!

 

[Hobden]

We have many damp issues for many reasons so obviously need to dry it out.

If there's a lot of moisture being generated internally it might be a "quick fix" to tackle that first? Maybe the wallpaper would start to improve at that point (although if, like us, you don't like wallpaper, then now would be a very good time to start stripping it!). The place hasn't fallen foul, internally, of the damp-proofing mob has it? This chap seems to talk a lot of sense -

http://www.heritage-house.org/rubbish-taken-from-the-damp-companies-websites-.html

The brickwork behind the render is soaking and makes a clay instead of dust when drilling into it

Are there any excessive external sources of moisture? High water table? High ground levels? Broken guttering? Cracked render letting rain in? If so, tackling these might help a little, though getting the render replaced long term seems like a good idea to me - but only from what I've read, I have no personal experience of this (yet!).

 

[malcolm]

I would start chipping away. It will help the wall dry even in winter and it makes you feel good! It might be a precaution not to strip if the weather will be freezing day and night over the following few days as the sodden bricks might suffer more frost damage. After a few days the surface should dry and insulate so frost shouldn't be a problem any more.

 

[Zebra]

It makes little difference when. I agree with Malcolm, I would start chipping away. It'll take ages, inevitably, so it'll be summer by the time you get it all off
Mine was bare, too, for about 2-3 years ( approx 300 year old soft red bricks) and no spalling occurred. It did however allow me to make sure I had addressed all the causes of damp before I undertook the re-rendering. (There may be more than one cause!)

 

[Easrow]

Thanks for the quick replies. Some of the moisture issues I can see are the concrete render, concrete path around the whole property that is only a couple of inches lower than the inside floor, inside floor has concrete over the original flagstone and quarry tiles with a bitumen layer between, the inside has been re plastered on the lower half with gypsum so I guess Mr rising damp salesman has been in...Although I think this was a good few years ago looking at the decor, the kitchen has no extraction, and all walls have many modern coatings. So a few things to address. We have already dug up ghe concrete in one sitting room and exposed the flagstones, removed all wallpaper in there too and it's drying out ok. We have also opened up every fire place as they were all blocked or capped with no through ventilation. In fact the chimney sweep was here yesterday and we lit a fire the same evening. One step at a time eh?

 

[88v8]

At the risk of stating the bleedin obvious, start from the bottom. Once you get above 3-4ft, in terms of immediate damp amelioration you'll be into diminishing returns.

If there is garden around the house with established plants that you value, this is not a bad time to be doing the work. The mess and the trampllng are better tolerated when the plants are dormant. Remove all the debris, otherwise it will have a negative effect on the soil.

As soon as you can into the job, try to get a sense of why it was rendered. If you are finding structural problems underneath the render, stop and have a think. Otoh, it may be that it was always rendered and the cement was simply an ignorant replacement of a life-expired lime render.

Beware around windows and doors - the render may be providing a waterproofing function at the wood/brick interface which you would need to make good with mastic.

Ivor

 

[Easrow]

The house has always been rendered from what I can tell as I found an old photo from 1903 and it still looks the same. So I reckon at some point it was modernised and they were sold cement render. It has hairline cracks and gone hollow in lots of places so is not really doing its job. I'm planning on digging a french drain soon to help any moisture escape.

 

[malcolm]

The French (and that Mr French) don't know anything about drainage - it's Zebra you need for this sort of thing - http://periodproperty.co.uk/forum/viewtopic.php?f=1&t=14035 A drain filled with gravel will be wet below the surface, so while it is useful for draining surface water it can be less good for drying out a wall.

After 5 posts your replies should appear without delay. Have you posted any pictures yet? That would get you over the mark.

 

[Bevmarley]

I would be careful about the french drain as that is what we were going to do around our house but then read that it could cause subsidence(my worst nightmare) if you have shallow foundations as we do. Apparently it would be better to have an open drain.I will try and find the article.

 

[Easrow]

OK I'll look into that then. I won't be going down that far really, just so it's lower than the internal floors. I think it's just been built up over the years and now has concrete on the top. The foundations look reasonabe. I could do without subsidence though. I've read through the link malcolm suggested. The grate looks good but the ground around our house is not as high as theirs. I may have to do something like that on one side though as it is publicly accessible. I'll have to take some pictures.
But back to the topic...no one had any issues removing render in the winter then?

 

[88v8]

... no one had any issues removing render in the winter then?

Just bear in mind that the render is keeping the rain off ... and the frost... and to an extent may be acting as a stressed skin and holding the house up so be prepared to stop if you find the walls underneath are unsound.

Ivor

 

[Easrow]

Sounds like sound advice to me. I'll have to have a poke around and see what I find

 

[Flyfisher]

I can't see any real problem with removing problem render at any time of the year though I'd be mindful of weather issues as mentioned above, particularly if the underlying bricks are as sodden as stated and frosty weather is likely. I'd consider some form of protection for the newly bare brickwork while it dries out, bearing in mind that a rule of thumb is one month per inch depth of wall, meaning that a totally sodden wall might easily take around one year to fully dry out.

We had an area of rendered chalk block/flint rubble wall that had been extensively damaged over some considerable time by a leaking downpipe. Fixing the downpipe was pretty easy but the render had come way from the wall in places and everything was soaking wet and quite loose as the render had been holding the wall together - a scenario that Ivor mentioned above, albeit not with underlying brickwork. I removed the worst of the render while leaving enough to keep the wall held together, the idea being to improve ventilation to the wall structure but not to weaken it too much.

I then fixed some 2x1 treated roof battens across the damaged area of wall and covered it with breathable roofing membrane, the idea being to protect the wall from further rain and frost while allowing it to gradually dry out. As I had plenty of other more urgent things to do, the wall remained that way for the next few years (I forget exactly how many). When the wall was finally repaired (actually dismantled and rebuilt, but that's another story) the structure of it was still quite 'loose' but it was bone dry right through. I've similarly used breathable membrane in a few other instances where I've needed temporary weather protection for parts of the house, stocks of timber and even for some tractor implements that had to be left in the open over winter. It's a great way of keeping things dry and protected without incurring the problems of 'sweating' and condensation that so often occurs with tarpaulins and other forms of coverings. It's not necessarily 'pretty' but it most certainly functional!

 

[plasticpigeon]

Cracked render is no good as it lets water in, but little of it can evaporate. A horrid job this time of year though, it might be worth waiting till spring just because it is more pleasant for you that way. Covering like FF suggests with roofing membrane is an ingeneous solution! It sounds like you have already made a very good move by removing the concrete path, so that the slate damp proof course can actiually do its job, I hope this helps. You know we all like pictures here! The style of your house will give some idea as to whether it was rendered when built, as will the quality of the brickwork when you take the render off. I hope you can salvage the flags and quarries, they are lovely floor finishes.

 

[Easrow]

I've tried to upload some pictures but they are too large. I'll have to see what I can sort on the computer instead of from my phone. But for now I'll describe it. Built in 1847 on the site of an old poor house...probably using some materials from the demolished building. It's detached. Made of solid brick and rendered. I think always rendered but we will see. Red clay triple romantic roof tiles with cat slide rear. It's been re jigged over the years internally but not too majorly. The two reception room have both had the windows enlarged. Only one old window left in the house which is in what we think was the old kitchen. There are no extentions.