Dry line uneven exterior wall

[willcm]

Hi all,

I've just bought my first house but it needs a lot of work doing to it To save costs im looking at doing most of it myself.

I've stripped back the walls to masonry as the lime plaster that was on it was in a real state and crumbling. the external walls are stone, the inside of which are pretty uneven. My plan is to timber frame them by knocking timber noggins into the gaps in the stone to even the wall out and then build a frame onto that - is that the best way given that i'm no good at plastering? (the house will all be skimmed by a plasterer once I've drylined)

I plan to use builders paper to keep external moisture out but allow internal moisture to pass through, I've heard conflicting advice as to whether to put this on the exterior wall side before the insulation etc or internal side before the plasterboard - what do you guys recommend?

Finally I will put kingspan in the timber frame and may even build another timber frame over that to allow the services to pass through i.e electricity wire network cable etc without disturbing the insulation.

Will this keep damp out because I dont want to have problems down the line with that because I've also heard that because some of my walls are damp that i'm better keeping a 50mm gap beween the exterior wall and the timber frame?

 

[1john]

Why not just build a stud wall infront of the wall and half or three quater fill it with celotex leaving the rest free for services.

 

[ajrobb]

http://www.british-gypsum.com/systems/system_selector/gyplyner_universal_lining.aspx

 

[willcm]

Thanks for the replies, the reason I don't want to leave 3/4 or 1/2 uninsulated is that it's a cold external wall I need all the insulation I can get to keep the house warm! What's the thinnest kingspan that still remains useful thermally?

That Gyplyner system looks great - are they damp proof? Looks like it could save me a load of time knocking the masonry to fit my timber noggins and would allow the services to effectively fit behind the insulation. Would the tracks have the depth to hold kingspan - or could i even attach timber to the brackets to ensure that it does?

 

[plstering]

Gyplyner system
is the nuts m8 just black jack the walls first then fit the stud work i use it all the tme at work quick and easy coat the walls good and proper
let it dry over night
use hammer fixings for the clips or use my toy
http://cgi.ebay.co.uk/Hilti-GX100-N...Home_Garden_PowerTools_SM&hash=item3f0411f64b
then its just a case of plumbing up the clips cut them back with tin snips
screw up the c studs fill the voids with insulation then start fixing board useing 12.5mm 8*4 boards

mark it up at 600mm cwnters

 

[plstering]

you can get all the c stud self taping screws plasterboard screws boards scrim plaster from wickes nice and cheep but you can get the clips from jewsons.
were in the us you from m8 as id come and put up all the stud work for you if you want.

 

[ajrobb]

Thanks for the replies, the reason I don't want to leave 3/4 or 1/2 uninsulated is that it's a cold external wall I need all the insulation I can get to keep the house warm! What's the thinnest kingspan that still remains useful thermally?

A sealed 20 mm reflective cavity has an R value of 0.6. This is equivalent to 15 mm of PIR or 25 mm of mineral wool. Add 20mm of Kingspan K18 and you have an R value of 1.4. The foil backing on the K18 is low-emissivity, so creates the reflective cavity for nothing. You need to seal the edges of the cavity or its U value drops to 0.4.

That Gyplyner system looks great - are they damp proof?

They are galvanized steel and can be used on external masonry walls.

 

[willcm]

Cheers guys,

Couple more questions will the Kingspan friction fitted between the Gyplyner be okay or will this cause thermal bridge issues? If so how am i best installing the Kingspan?

Where does the builders membrane go - on top of the insulation before the plasterboard - i.e. room side or on the external wall before the insulation - i.e. wall side as I've had conflicting recommendations as to which one prevents condensation build up.

 

[plstering]

no just black jack the walls fit the clips and stud work fill the voids then board no need for builders paper

 

[willcm]

But I've been told that because it's an old sandstone wall that the walls need to breathe - would blackjacking not cause more problems with water being retained in the wall?

So do you recommend using something like kingspan kooltherm k18 rather than seperate insulation and board?

 

[ajrobb]

Have a look at http://www.heritage-house.org/

Yes, they recommend a ventilated cavity between dry liner and bare stone. Drop them an email, one of them, Peter Ward, lives in a stone house with dry lining on gypframe, so should be sympathetic.

Ventilating a reflective cavity only loses 0.2 R value (equivalent to 5 mm of PIR) compared to a sealed reflective cavity.

If you have separate insulation boards, they can be between the frame and the plasterboard. Tape the joints between insulation sheets to complete the vapour barrier.

 

[plstering]

the far end of the wall is stone m8 external wall just black jack it and away you go m8