Insulating single brick bay with Gyproc ThermaLine SUPER

[jimboH]

Hello

The upstairs bay windows in my house are single brick and over time mould grows on the inside wall.

I was planning to insulate the area with 90mm Gyproc ThermaLine SUPER insulated plasterboard and bond the boards to the wall with Gyproc Dri-Wall Adhesive.

My concerns were:

1. do i need to strip the wall back to the bare brick?
2. do i need to treat/paint the wall to seal it before I fix the boards.
3. should i use wooden battons instead of Gyproc Dri-Wall Adhesive.
4. the insulated boards have a perforated layer covering the insulation - is this the vapor barrier? or should i just peel this off as it looks like it'll come off anyway!
5. I was going to butt joint the boards together. do i need to cover the joints with anything?

 

[freddiemercurystwin]

You sure its single skin brick and not timber frame?

 

[foxhole]

Mould grows because you have insufficient ventilation, insulation is not a solution, the mold will move to the nearest cool surface.

 

[jimboH]

Its not a timber frame.

I'm aware that ventalation will reduce mould but the room is cold and need insulating anyway.
I though by adding insulation there might be a chance that the inside wall wont be as cold and might get rid of the mould if not then i'll add some vents.

 

[freddiemercurystwin]

Lack of insulation can cause mold growth, the cold is condensing on the coldest surface of the external walls; the single skin.

 

[foxhole]

Lack of insulation can cause mold growth, the cold is condensing on the coldest surface of the external walls; the single skin.

Lack of insulation itself does not cause mold growth, you still get mold on well insulated walls.

 

[freddiemercurystwin]

A wall with no insulation will encourage condensation and mold growth. Ventilation on its own is often not enough to prevent condensation in buildings with inconsistent insulation.

 

[jal]

have a look at my thread on internal wall insulation - i had the same problem..

 

[freddiemercurystwin]

Is it just bare brick on the outside or rendered? Has it always been dry? In any case I would be stripping off the plaster, coating with a couple of coats of RIW (bituminous paint) and then fixing timber battens then screwing your thermaline to these. Butt the joints up close. Skim over the lot.

Not sure what you mean when you say perforated layer, does it not look like this;

This may be of use http://www.british-gypsum.com/pdf/SB07_DriLyner_04.pdf

 

[jimboH]

Thanks Jal interesting thread.

The house is rendered on the outside.