Cement render on timber frame

[sarah46]

Help!

I have a timber framed house c1800 with cement render on exterior, which has been sprayed with a plasticised type coating about 15 years ago I think. This coating is now peeling off and the time has come to do something to the exterior of the house. the question is - what??

On moving in 12 years ago we had some repair work done from the inside, without disturbing the render, - basically the sole plate and many of the smaller timber uprights/infill were damaged by damp around the base. These were cut back to sound timber and the walls bricked up to height of about 2 feet, with a new plate tying them in to main uprights. some other interior uprights were exposed and found to be OK - we have left these exposed. Condition of the rest of the exterior wood is not known but presumed OK in the absence of any evidence to the contrary.......

We have sought advice about what to do with the render - one suggestion was that it could damage the original substrate badly if we try to remove it, and we should strip the plasticised coating off and paint the render with a breathable paint. Another is to strip coating and apply a tyrolean finish.

I know the purist answer is to strip back to basics and start again but I am terrified of the likely cost of this and I would welcome any suggestions please - I am having sleepless nights worrying about it!

Sarah

 

[NT]

quote sarah46

>We have sought advice about what to do with the render - one suggestion was that it could damage the original substrate badly if we try to remove it,

what is the original substrate?

> and we should strip the plasticised coating off and paint the render with a breathable paint.

will still retain damp

> Another is to strip coating and apply a tyrolean finish.

as bad as now IIUC


> I know the purist answer is to strip back to basics and start again but I am terrified of the likely cost of this and I would welcome any suggestions please - I am having sleepless nights worrying about it!

If you diy I cant see it costing much. Lime is around £6 for a big heavy bag, and sand £2. Limewash is £6 per dustbinful. Also you can do a patch now and then, take your time over it. So whatever way you go I dont think you need worry about cost, unless youre brassic.


NT

 

[middi]

What to do ?.
There is no need to loose sleep over the decision.
It basically depends on two main points.

1) do you want the building to just look pretty and compromise its future long term survival ?

2) do you want the building to look very pretty with the emphasis on restoration.

Once you have decided what you want most , after long arguments with you conscience and your pocket just go for it .

If the answer is 1), you might as well slap another load of plasticky artexy paint on it. ( God forbid )

If the answer is 2), and as NT said, the raw materials for re-rendering in lime plaster are not very expensive at all.

The truth is that you have a building, like many of us, Which has been damaged by bad addition and repairs by the passage of time of the last eighty years or so.

The truth is, as you probably know, you building started life with simple frame and wattle and daub, which was good but draughty, improvement on this was to lath an plaster the outside, also good and less draughty and when this deteriorated the next step was to clad the outside with boarding, also just as good but much quicker to repair.

The problems really started when cement came on the scene, what better than nail some wire mesh on any existing wooden exterior, make a very strong cement mix and this would not only solidify the building it would make the building indestructible ( or so we thougt).

We were definetely right about holding the building together for a while, even after the woodwork had rotted because it could not breath.

So, thinking about these lines as to history of " progress" in old building repairs you can make your decision.

 

[sarah46]

thank you to middi and NT for replies.

I'm not sure I would be able to tackle the hacking off cement render and doing the lime rendering myself as it is a large surface area -do you have any rough guide as to how much I might have to pay to get this done - eg a per square metre estimate? And how I might go about finding someone to do this (Bedfordshire) - looking in Yellow Pages etc doesnt seem to help when looking for specialists like this.

Also, if there is rotten timber and any damp infill I wouldnt have the expertise to deal with this either!

I did read on the SPAB website about the possibility of removing cement render just near the bottom of walls if it is adhering very strongly to the timber/infill and replacing these areas with lime plaster. I have tried to call them about this but cannot get through to a real person . I wonder if anyone has any views on this?

 

[biffvernon]

removing cement render just near the bottom of walls if it is adhering very strongly to the timber/infill and replacing these areas with lime plaster.

That sounds very sensible. The problems will probably be worst low down so set yourself the target of restoring the bottom yard of wall to a naturally breathing structure made from vapour permeable materials.

You can leave the rest of the house till later when your biceps have grown.

 

[NT]

Sarah,


Just doing the bottom section sounds a workable options to me too. It would save you a lot of work.

An sds makes cement removal pretty quick, whether its a good idea depends on more details of building construction. If for example its wood frame, metal mesh and cement on the outside and PB inside, sds would be quite safe. If OTOH theres lots of ancient fancy plasterwork inside and brick infill it wouldnt be.

No idea what it'd cost to pay an expert. If theres nothing fragile under the cement, ie no bricks or lime plaster, unskilled labour is £5 - £7.50 ph.

If you find any rotten timber you can come back and ask.

Projects like this tend to take time, during most of which nothing much is happening. As well as work there's reading up, asking questions, and of course getting on with the other 1000 things life demands.


NT

 

[sarah46]

Thank you NT, can you enlighten me on your abbreviations - you are dealing with a novice here!....

What are sds, PB and OTOH please?!

As far as I can tell, the construction,( other than the areas around base of house which have been repaired from the inside where the studs and infill have been removed as destroyed by damp and now bricked up) is timber with daub?(straw/mud etc), infill with lathes covered by cement, so that the cement appears to be adhering directly onto the lathes. I cant see any evidence of a wire mesh.

This is why Im a bit worried about hacking off cement in case everthing comes with it! Perhaps we should just try a bit and see what happens?

If we did just do the bottom section of the house, do you think it would be ok to finish the whole house with a limewash even on bits which would still have cement on?

Thanks for your help - all comments and suggestions very gratefully received!

Sarah

 

[sarah46]

just realised OTOH isnt a technical term!!

 

[NT]

quote sarah46

>Thank you NT, can you enlighten me on your abbreviations - you are dealing with a novice here!....
>
>What are sds, PB and OTOH please?!

sorry. SDS is a type of hammer drill that will hammer without rotating, put a chisel in it and its great for light to medium cement removal work.

PB = plasterboard, modern plaster sheet.

OTOH = on the other hand


> As far as I can tell, the construction,( other than the areas around base of house which have been repaired from the inside where the studs and infill have been removed as destroyed by damp and now bricked up) is timber with daub?(straw/mud etc), infill with lathes covered by cement, so that the cement appears to be adhering directly onto the lathes. I cant see any evidence of a wire mesh.
>
> This is why Im a bit worried about hacking off cement in case everthing comes with it! Perhaps we should just try a bit and see what happens?

If damp has caused damage already, I suspect that would be the thing to do, as it seems theres a sound reason to strip the dement off. Wood laths are flexible, so wont mind some hammering. Daub I dont know enough about.


> If we did just do the bottom section of the house, do you think it would be ok to finish the whole house with a limewash even on bits which would still have cement on?

yes, sure. I can see youre going to end up with this all done. Maybe for £100.


NT

 

[sarah46]

NT,

thanks again for your input- I am feeling a lot happier now and am almost looking forward to releasing this poor house from its misery!Wheras as the weekend I was feeling practically suicidal!

Sarah

 

[NT]

Good to hear that. I know what you mean, when it looks horribly complex, essential and awfully expensive. I've always found though that the reality is it isnt, just a matter of taking the time to find out how to do it all. Once youve done a couple of jobs like that nothing will phase you. Thats when you become really dangerous

Do talk to someone before you do the underpinning.


NT

 

[Penners]

Sarah - just a brief PS on one of your original questions. There's absolutely no point in painting the cement render with a breathable paint. The cement won't breathe, so the breathable paint won't help anything at all.

 

[Gervase]

Just adding my 2p worth here..
You need to get rid of the cement render. You can either pay a lot or a medium amount, and the end result will be little different. A pro will charge you a lot - £25sq/m min for stripping off the old paint and render. Instead, find a gap-year student and pay him/her £5.50 an hour and get it done a lot cheaper.
Apropos the SDS - a lot of percussion masonry drills (Makita and de Walt etc) can chip off cement, but they don't really like doing so - they'd rather be drilling round holes in masonry. Consider hiring a proper demolition drill instead, and make sure you ask the hirer about insurance. The motors often burn out and will cost around £70 a time to repair (believe me, I've been there ). You don't want to be paying this yourself, so get insurance. Either that or hire a full-sized Hilti or Kango demolition drill for around £25 a day and find someone with forearms like Popeye to wield it.
Ah, that's where the student comes in...

 

[Gervase]

I am terrified of the likely cost of this and I would welcome any suggestions please - I am having sleepless nights worrying about it!

Sarah

...and believe me, the cheapest option in the long term is the purist option. And it's also the most attractive and the one that adds the most value to the house. It's as simple as that.
Oh, and it's also the one that will be the most enjoyable to have a go at yourself and which will teach you the most about how your house was built and help you, in that Forsterean sense, to 'only connect' with the people who built it.
Don't be terrified and sleep well - it seems to me as though you've already made the right decisions.

 

[biffvernon]

...in that Forsterean sense,

Congratulation, Gervases, 'Forsterian' returns only one result from Google.

Yes, the violence of the first chapter of The World in the Evening is not at all Forsterean.

For instance, Dostoyevski is essentially a comic writer. I think at least The Brothers Karamazov is the greatest sort of farce ever written. There’s something in Dostoyevsky that you find in the life of Francis of Assisi and that was very much in Ramakrishna. Farce and truth became identical in the most drastic manner in the great scenes with Zossima; and, of course, in the murder, the whole thing is this farce which is heightened to the utmost.

 

[middi]

The already suggested idea of removing the lower half one meter of cement render and carry ou repairs with appropriate materials is a good starting point, obviosly it would be better if you could take off all the hard render in one go and get it over and done with.

As to using cement breakers ( drills, kango,s, etc..) I would be very surprised if you should need any of these at all.
Wired old cement render is usually very easy to remove, a couple of good handyman can remove all this stuff from a whole house in a day.

You will need:-

An angle grinder with diamond blade and goggles
one or two heavy duty crowbars
A very strong flat steel shovel
and scaffolding ( if you doing above first floor level)l.

The idea is to cut, or heavily score the old render, in approximately one square meters and " jerk it " loose from the studs or boarding which is attached to, the cut section will fall of in one lump.
You can achieve this by sliding rhe flat shovel behind the section you have cut and counterlevered against the studs or boarding.

Get rid of the rubbish, and finally apply an appropriate cladding of your choise as long as you don't "suffocate" the building.

 

[sarah46]

Thanks everyone - I will let you know how I get on!

 

[Silas]

Just read this thread with some amusement sarah46 has some peeling paint on the outside render. She has not mentioned any other noticeable problems she dose not say the house smells damp and musty nor is it mouldy and full of cracks, some works a few years back repaired damage from the inside and after what sounds like a good check over didn’t find any other problems. Now thanks to the advice here sarah46 has a kanko drill in her hands and is poised to attack the render of her house from the bottom up no less! Slow down people what if the sole plate and attached beams under the render are crumbly cake?. Please sarah46 get a pro to have a look, a builder who knows old buildings a sympathetic surveyor, get several opinions but for now PUT DOWN THE DRILL. Inspect assess
and take appropriate action when you have a clear picture.

Oh dear the paints peeling that wall will have to come down...not
:lol:

 

[biffvernon]

It's a timber framed building not a cob, so the render will not be supporting unsupportable mud. Sarah's work with the drill is not going to bring the house crashing down. Pick up the Kango again #46!

 

[sarah46]

Wow-Never thought there'd be so much interest - perhaps I'd better have an open day!!

Seriously though, I have found a local guy who repairs/maintains old properties - he has been to have a good look round and we have decided as a first step to open up two corners where there is some cracked render, and investigate some other areas where render has cracked to see what damage any moisture ingress has done , and then take it from there. Also intend to speak to a surveyor too.

So I wont pick up the kango drill just yet, but I have started poking around with the chisel!

Sarah