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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Building Questions >> Wall Insulation https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1547572956 Message started by mike4369 on Jan 15^th, 2019, 5:22pm

Title: Wall Insulation
Post by mike4369 on Jan 15^th, 2019, 5:22pm

Has anyone got recommendations on insulating a wall. I have looked at Graphine plus and WallrockKV600 (expensive!!)so far.

Title: Re: Wall Insulation
Post by woodsmith on Jan 16^th, 2019, 11:50am

This type of insulation isn't thick enough to give any real thermal benefit. What they can be useful for is preventing cold spots where condensation and mould form but it often just moves it to another part of the room. They are soft and the surface is easily marked so most practical in alcoves or behind furniture where they won't be touched. If you insulate a wall to reduce condensation it can push the damp onto the ceiling and then it's very difficult to use this type of insulation on a ceiling. It may be worthwhile seeing if anyone has reviewed these products on amazon if you want to check which one is best.

Title: Re: Wall Insulation
Post by thescruff on Jan 17^th, 2019, 8:09am

For what it's worth I have always favored Celotex, The Spec is certainly among the best.

Like everything it ain't cheap.

Title: Re: Wall Insulation
Post by CWatters on Jan 18^th, 2019, 2:22pm

Mike4369, I can't comment on the products you mention but...

Beware of companies offering "thin" insulation solutions. It's possible to generate a large percentage improvement compared to an existing uninsulated wall but the end result might still be very poor compared to say the current building regulations which you might be required to meet.

PIR (polyisocyanurate) insulation as made by Celotex or Kingspan is one of the best raw materials in terms of its performance per mm of thickness. I think only Aerogel is better (but not much better) and quite a bit more expensive.

Pretty sure both Celotex and Kingspan will have application notes on their web site for insulating walls.

If you have a single brick wall then realistically you should be looking at something like >50-60mm of PIR and 12mm plasterboard. (Would have to check the regs for the exact thickness required). You can get insulated plasterboards with the two combined but they might be more expensive than separate.

Title: Re: Wall Insulation
Post by londonman on Jan 20^th, 2019, 9:41am

CWatters wrote on Jan 18^th, 2019, 2:22pm:

.... You can get insulated plasterboards with the two combined but they might be more expensive than separate.

You can, yes. But we had some with only about an inch of insulation and TBH t was a waste of time. Heat loss prevention is minimal compared to a decent 100mm of Kingspan.

Don't forget, Mike, that you need vapour barriers etc as well.

Title: Re: Wall Insulation
Post by mike4369 on Jan 26^th, 2019, 11:49am

Just a bit more info. The insulation will be affixed to an outer wall in an upstairs bedroom - the wall is 2feet (approx) thick random stone, area of wall is about 100 sq ft and there is no damp. I had considered something like celotex but don't want to have to batten the wall and board over. Just a small % extra will suffice as its a spare room.

Title: Re: Wall Insulation
Post by londonman on Jan 28^th, 2019, 9:24pm

The wall thickness has no effect on heat loss. If anything it might increase it.

I still say that a 25mm bit of insulation on plasterboard is pointless. Especially as you don't have any condensation.