Attic Wall Insulation

okane1

I have an internal solid wall within my attic eaves which backs onto an upstairs bedroom. I would like to fit insulation to this wall by fixing battens to the wall, install 150mm roll Knauf insulation and then 60mm solid insulation board (xtratherm/etc).

Within the remainder of this attic is a stud wall backing onto the bedroom with 150mm insulation and I will fit 60mm solid insulation board.

As the wall is inside the attic do I need to install a membrane first?
On the photo the wall I want to insulate is to the right, with the house external wall on the left.

Right2Write

A dormer bungalow? Just curious, but why weren't stud walls used for internal partitions upstairs. Maybe it's structural but seems close to the gable or party wall. General principle is to use a membrane on the 'warm side' as far as I know, so the cool attic air, insulation, membrane, structure. But you wouldn't think that much significant internal room moisture will move through a 100mm block wall?? Other opinions may be more useful!

okane1

Yep a dormer bungalow built ~2000.

Steve

If there studding with insulation or just plaster on brick on the inside face?

If it is just plaster, then put up a membrane on the brick. The membrane should always be as close as possible to the 'warm' area AFAIK.

okane1

Steve wrote: »

If there studding with insulation or just plaster on brick on the inside face?

If it is just plaster, then put up a membrane on the brick. The membrane should always be as close as possible to the 'warm' area AFAIK.

Just plaster on inside face. Thanks for advise: Membrane, timber fixtures, roll insulation, solid insulation. Weekend plan made!

Steve

okane1 wrote: »

Just plaster on inside face. Thanks for advise: Membrane, timber fixtures, roll insulation, solid insulation. Weekend plan made!

I'm no expert on this, just my DIY opinion so maybe wait for other replies as well