dry lining,good job or not???

mr_mags

hi all,just a quick question about dry lining,my engineer is questioning whether it is really beneficial,his view is that the inner block acts as a kind of storage heater,and that the insulated slab prevents the warmth from returning to room,which makes sense.all opinions welcome,

No6

It also stops it becoming the storage heater in the first place, quicker heat up anmd cool down, over slower heat up and cool down, both valid although I have drylining in the old (1920) part of my house and it stays warm forever and the newer part (2001) with no drylining can be freezing at times

Slig

It is an easy way to bring up your U-values (debatable if it is practical as it gets punctured every time there is an internal wall joining the external)
It will however reduce your thermal mass.

If this is an issue then build all your internal walls of blockwork instead of stud partitions. Let them act as the heat sink and allow toe external walls to just stop the heat leaving the envelope.

AMIIAM

Dry lining is not at all necessary in properly built cavity walls. ie double wall incorporating insulation and a cavity. It was only necessary the old way (construction with cavity blocks). Oh, the builders used to love those. Also plasterboard is a builders dream again, covers up badly built walls.

Scober11

Nearly all the house's we build now are drylined but we also dryline the internal block walls. Our engineer and Architect love it. Most of the house's are one offs for clients and they haven't complained about heat loss or energy bills (so far anyways all running on gas).

muffler

AMIIAM wrote: »

Dry lining is not at all necessary in properly built cavity walls. ie double wall incorporating insulation and a cavity

Care to show us an example of this that complies with Part L and will get you a B rating

MacTheKnife1

Scober11 wrote: »

but we also dryline the internal block walls.

Scober11

That just seems like a step too far. Why do this? Is it the thermal bridging from where the internal meets the external??

Scober11

Yep suppose to be anyways. We use the 62 on the externals with 50 between the battens and 45 on the internals or sometimes 25 depends on what the Architect or client wants. Makes the frames a bit thicker but we rebate those and step them so it creates a thick looking wall, interior designers love it.

MacTheKnife1

Scober11 wrote: »

Yep suppose to be anyways. We use the 62 on the externals with 50 between the battens and 45 on the internals or sometimes 25 depends on what the Architect or client wants. Makes the frames a bit thicker but we rebate those and step them so it creates a thick looking wall, interior designers love it.

Scober - easy on the terminology - you will lose me on this one. I suppose the 62 u refer to is a 62 mm insulation board? - but 50 between battens?? Is that 50cm between each batten?

Surely interior designers would prefer to keep the walls slim and easy to hang stuff on? By insulating the wall you get limited ability to hang stuff??

I am truly amazed that we might need to insulate internal walls. I viewed them as a huge asset to soak up thermal energy - but you suggest blocking them off altogether.

I plan on dry lining my external walls with 50mm of Xtratherm and 105 mm cavity of ecobead. But the internals downstairs will be uninsulated block.

Mac

Scober11

9 inch block 50mm xtratherm then 62mm slab. We only do what the experts say, i'm qualified in structural engineering so i take advice on thermal and then just add it all up:D

Technophobe

Hey all,

Trying my best to folllow thsi post but haven't a clue on this sort of thing....

This is what I have been recommended and was going to go with for my new build..

"All walls to be built with conventional cavity wall construction with an overall thickness of 320mm namely 100mm internal block, 60mm of thick foil faced Kingspan insulation fixed tight to outer face of inner leaf,. 40mm cavity and 100mm outer leaf block work.
The internal face of the external walls to be dry lined with 50mm composite plaster board/polyiso board fixed with screws/dabs and skimmed to a smooth finish"

Does this sound okay and could it be improved without a huge increase in costs....??

thanks...

sunnysoutheast

Technophobe - that's exactly what we have. There'll probably be advice on here to add a separate vapour barrier. We didn't as it was skimmed. Our p'board is fixed to the wall with the mushrooms.

Make sure your window reveals are suitable for this makeup - i.e. so you can wrap the insulated boards round the corner.

Also check that your electrician knows that the walls will have these boards on them, the switch and socket boxes need to be brought flush with the front face. The walls will be chased for cables.

SSE

Slig

Technophobe wrote: »

Hey all,

Trying my best to folllow thsi post but haven't a clue on this sort of thing....

This is what I have been recommended and was going to go with for my new build..

"All walls to be built with conventional cavity wall construction with an overall thickness of 320mm namely 100mm internal block, 60mm of thick foil faced Kingspan insulation fixed tight to outer face of inner leaf,. 40mm cavity and 100mm outer leaf block work.
The internal face of the external walls to be dry lined with 50mm composite plaster board/polyiso board fixed with screws/dabs and skimmed to a smooth finish"

Does this sound okay and could it be improved without a huge increase in costs....??

thanks...

The 300mm cavity wall with the 60mm Kingspan is an old wall buildup. Adding the dry-lining just brings up the U-value. Its a perfectly valid localised solution as it works on the bulk of the wall but everywhere an internal wall or a floor joins the external walls there is a cold bridge. If it isnt detailed properly this can result in mould growth.

A better overall solution would be to increase the thickness of the inner leaf and then increase the cavity and insulation in it to bring it up to the spec.

MacTheKnife1

sunnysoutheast wrote: »

There'll probably be advice on here to add a separate vapour barrier. We didn't as it was skimmed. SSE

Not sure I understand - why does skimming remove the need for the vapour barrier. Do most people not put plaster onto the plasterboard anyhow? So shy would skimming it avoid the need for the barrier??

sunnysoutheast wrote: »

Make sure your window reveals are suitable for this makeup - i.e. so you can wrap the insulated boards round the corner.SSE

Sorry - I do not undertsand this one either. Why might the window be unsuitable for it?

Apologies for the questions but I am on a learning curve here.
Mac

Slig

if you are using insulation backed PB the there is no point stopping when you come to a window. the PB should be returned into the window so the window frame has to allow for this extra 50 - 75mm (or blockwork stepped back)