Internal Insulation of 2 x 2m solid wall bedroom

[JT101]

Hi
I’m trying to insulate the internal walls of my 2m x 2m box bedroom with single skin brick walls. The room is in the upstairs SE corner of the house, and suffers from damp in the winter. Almost certain it is condensation caused hitting a cold wall.
Anyway, I want to try to eliminate the damp and insulate the house at the same time. Prepared to lose up to 50mm of room with a budget of around £200 for an area of approximately 6m2. Got a few questions:

1. Can anyone suggest some materials with the best real world u-values (not hot box test) for the money & preferably as environmentally friendly in manufacture as possible (not so concerned about embodied energy, more the toxicity in manufacture and breakdown at end of life)
2. And of those materials, is there significant gain going from 20mm to 50mm. Obviously space is at a premium for me.
3. And how can I avoid cold bridging if I want to mount shelves on that wall with screws?

Thanks so much. Hope that’s clear

 

[freddiemercurystwin]

You will need to improve the ventilation as that is what causes condensation. Insulating alone will not solve it.

25x50 studs at 400 ctrs with 75mm or thereabouts of Celotex or Kingspan and a layer of plasterboard on top is pretty standard. 25mm will be better than nothing but not that great.

 

[JT101]

Done some research and it seems Fermacell or some other gypsum/fibreboard materail would be ideal. A low thermal conductivity 0.032 W/mK, made from recycled material and pretty much non toxic at end of life.

But it seems it's a dutch product, and I can't find any convenient suppliers locally. Can anyone recommend a similar board in the UK for internal wall insulation for single skin 9inch brickwork. Doesn't have to be gypsum/fibreboard.

Thanks

 

[DAZB]

Is this any use to you :

http://www.fermacell-drylining.co.uk/stockists-&-installers

 

[mointainwalker]

it seems Fermacell or some other gypsum/fibreboard materail would be ideal. A low thermal conductivity 0.032 W/mK,

Read

Yes, but that is for one metre thick. What thickness are you thinking of applying ? An ordinary 10/12 mm sheet isn't going to do much and it is a fairly expensive product for your budget.

You also need a vapour barrier behind the wall-board to prevent condensation within the wall.

 

[JT101]

Ah, I think i got confused with all the u-values of various products. It's actually 0.36 not 0.036, which makes a hell of a difference. Hence the sales guy suggesting I put rockwool with it.
Seems some sort of fibreboard with drylining and vapour barrier might be best. Any recommendations? I really can't go any more than 30mm after having spoken with the governor!
Wonder if I can decorate direct onto wood fibre without the plasterboard?

 

[mointainwalker]

30 mm really is bugger-all, although having said that, the initial insulation brings the biggest saving per cm.

Not sure if plasterboard plus 20 mm polystyrenene for dot and dab exists.

. . And how can I avoid cold bridging if I want to mount shelves on that wall with screws?

Different answers for different weights. How big a shelf and how much weight ?

 

[JT101]

Lets say 6ft by 1ft shelf with a shedload of books on it, which is what I currently have. I mean big books. So let's say 30 books, 1kg each