Solid wall (approx 220mm) dry lining and insulation

[AnthonyE]

First of all, Hi all, new to the forum.
We recently bought a 1890's gatekeepers house which has been extended (some ago, probably 1900's) to the rear with a solid brick construction (full height with suspended timber upper elevation) and to the side with a lean-to stone-built kitchen.

I suspect we'll be using this forum a lot to pick the collective brain of DIYnot.com, so thanks in advance.
We are tackling this project room by room and we are starting with the largest room - the rear extension lower level, which will be our main lounge when completed. the upper level is in good condition so we'll be living in there for the time being.

All the old plaster is coming off (damp damaged from being vacant and blocked guttering etc) and we'll remove all back to original brick work. I have already exposed the chimeny breast which looks like this:

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• AnthonyE
• 5 Dec 2011
• 2

we intend to leave this exposed after taking it back to the original arch and supports with either a wood burner or open fire (depending on fundage!).

That's a bit of background, now for the first quandary...

We need to insulate it. as mentioned it's solid wall and we intend to dryline but I would like to know your collective thoughts on using insulation between the battens vs insulated PB. is one any better than the other, could we do a belts and braces approach and incorporate both (I am not too concerned about losing space internally as its a big room).

Also, and I am aware of the contention surrounding it, but is it worth us providing DPC (injected or otherwise) as we're uncertain if there is a slate DPC present and we cannot rule out penetrating damp from below until we've sorted the drains and external ground levels (these being level with inside and concreted). We are on a tight budget and I think we should at least get the walls right first time hence us wanting to make sure we don't have to remove the plaster to do the DPC at a later date!

The damp and timber survey people quoted £2300 for a cavity wall membrane system to be installed in this room and I have yet to understand why, considering it's not underground (either fully or partially), this system was suggested over batten,celotex and PB?? anyone?
That didn't include the £700 for the DPC they wanted to inject around the perimeter

I am aware that a little knowledge is a dangerous thing, but we cannot afford to pay someone to do the work and besides - where's the fun in letting someone else do something I can do!

I think I covered everything. any questions, please ask.

Thanks,
Anthony

ps here are a few other images of the room before I got hammer happy on the fireplace.

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• AnthonyE
• 5 Dec 2011
• 2

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• AnthonyE
• 5 Dec 2011
• 2

This image (below) shows the gable end of the extension and the external floor levels

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• AnthonyE
• 5 Dec 2011
• 2

Thanks

 

[fmck]

A few notes to consider.
The dpc injection system can be done from hiring the kit from tool hirers such as HSS + supply of the liquid dpc.

We did a old building recently with solid walls. (school) We had heavy duty polythene on the walls then stud, mineral/ glass wool insulation and plasterboard. This is obviously the cheapest method but you can reduce the thickness with expensive foiled insulation.

 

[AnthonyE]

Thanks for that. Although we are on a budget we don't mind spending money on insulation as we can mitigate it though increased thermal efficiency.
We can compromise on the less important things like flooring and finishings!

 

[Simon.B]

Hi, doing a similar thing myself, but I’ve started in the back bedroom.

I’ve gone for 75mm battens and Celotex, with boarding screwed on the front.

I can do all this myself and if I use tapered edge boards I should be able to get away with just skimming over the joints. It also allows me to run services behind the Celotex and provide hard points for mounting radiators etc.

Cheers,

Simon.

 

[marklamond]

Looks like a good project. I'm doing something similar myself.

When you have the plaster off i would let the walls dry out and look for remaining sources of damp. It might take a while to dry if some areas are saturated. Sorting the ground levels could easily solve any rising damp issues naturally - cheaper too!

Some would suggest using breathable insulation and lime plaster etc, but that will cost a lot more in materials and time learning the skills required.

I would think carefully before doing anything a damp and timber company recommend as they tend to suggest expensive and overly technical solutions to simple problems that don't address the root cause. And they'll only suggest something from their repertoire, not what's necessarily needed.

It's likley there will always be some damp in the wall, so let it breathe. I would leave a gap for air circulation behind the studwork and have that open to the roof void, it looks like you have cement render outside? If that's the case any damp in the wall will be inclined to travel inwards. With a gap for air circulation, it can at least get out. Making sure the roof space is well ventillated too of course.

Insulated plasterboard will allow you to eliminate cold bridging through the studwork. If you don't mind losing a little more space it makes sense.

A woodburner or fire will look great in that room and help keep any damp out of the chimney breast too.

Would be good to see more pics as you take the plaster off.

 

[masona]

Also, and I am aware of the contention surrounding it, but is it worth us providing DPC (injected or otherwise) as we're uncertain if there is a slate DPC present and we cannot rule out penetrating damp from below until we've sorted the drains and external ground levels

Please do a search on here regarding damp issues, be very careful and don't waste your money on rising damp and treatments, it is one of the biggest rip off.

 

[ferdinand2000]

Ran across the thread.

Perhaps the first thing I would do would be to drop the external ground level by about 12-18", and see if it made a difference.

We did, and it helped for a house with stone walls.

It wasn't concrete, though .

Ferdinand