insulating an external wall ? help

[steveo3002]

weve got a small section of external wall thats single layer , its north facing and very cold in the winer so attracts condensation

i plan to board it up once the spring comes , would i be right in thinking a frame of wooden battons, then foil backed plasterboard ? with the option of stuffing the gap with rockwool?

how thick battons do i need ?
is rockwool the right stuff ?

its a smallish area about 4x8ft

[ssray]

http://www.insulation.kingspan.com/uk/pdf/k17.pdf
Any good?
Ray

[herbialfa]

Nail a vapour barrier to the wall.

75 x 50mm battens with 75mm of Celotex (or something similar) between the battens.

12.5mm plasterboard & 3mm plaster skim

Jobs a good un

[Mr GrimNasty]

For such a small area just use a sheet of foam insulation(50mm minimum)/plasterboard laminate.

[steveo3002]

Mr GrimNasty said:

For such a small area just use a sheet of foam insulation(50mm minimum)/plasterboard laminate.

onto battons or direct to the wall?

[MrV]

steveo3002 said:

Mr GrimNasty said:

For such a small area just use a sheet of foam insulation(50mm minimum)/plasterboard laminate.

onto battons or direct to the wall?

SSray already gave you the link to the stuff you can just fix to the wall

[C Lee Farquar]

I would use the insulated plasterboard sheets, as already recommended, most builders merchants sell them. Dab fix them, best to avoid timber fixed to a 4" wall.

They can make a huge difference.

[petercam]

steveo3002 said:

weve got a small section of external wall thats single layer , its north facing and very cold in the winer so attracts condensation

i plan to board it up once the spring comes , would i be right in thinking a frame of wooden battons, then foil backed plasterboard ? with the option of stuffing the gap with rockwool?

how thick battons do i need ?
is rockwool the right stuff ?

its a smallish area about 4x8ft

Your problem is going to be water penetration from a single skin brick wall. You either need to make a barrier, or vent it to allow it to dry. I recently insulated 2 utility room walls about 8'x 8' each, by applying a bituminous coating (2 coats) to the walls and floor before framing, insulating and plasterboarding the walls. Over this cold and wet winter I've had no damp or mould problems. If you go down the ventilation route, you will have to put in an air brick top and bottom and leave a minimum of 1" gap between wall and framing to allow the air to circulate and dry the cavity. If you coat the brickwork you can put the framing tight against the wall.

[ShredderXLE]

herbialfa said:

Nail a vapour barrier to the wall.

75 x 50mm battens with 75mm of Celotex (or something similar) between the battens.

12.5mm plasterboard & 3mm plaster skim

Jobs a good un

No...do not nail a vapour barrier to the wall.....if you put anything directly on the wall it should be a breather membrane (ie building paper) The Vapour Control Layer should go over the warm side of the insulation...this prevents moisture passing through the insulation lining and condensing on the cold face of the wall.

I would;

1. Strip any paint and old wallpaper off the wall to expose the brickwork and allow any damp to fully dry out.
2. Fit 50mm celotex or kingspan insulation boards over the wall and then tape the joints with a foil tape and seal perimeters of the insulation boards with wall, ceilings and floors with a continuous bead of sealant (this forms the vapour control layer....if in doubt about the quality of workmanship, install a polythene VCL with lapped and taped joints)
3. Over the insulation boards fix 25mm x 50mm treated timber battens at 600mm centres screwed and plugged through the insulation and back into the wall.
4. Overline battens with plasteboard....the batten void behind allows cables to be passed down.
5. Make cup of tea.

[Road2Ruin]

Just had this done at our house. The wall was solid stone and about 5.5m by 2.5m and freezing in the winter. The old plaster was stripped, the wall then had 2 coats of Aquaproof, 2 inch battens fixed, 45mm Celotex (or equivalent),a breathable vapour barrier put over the top of all of that, then plaster board and skim. Now room is really toasty.