Insulating chimney alcove

[brightondiynotfan]

hi there,
Alcove next to the chimney breast is filled with book shelves, floor to ceiling. Trapped air, cold brick walls = condensation problem!

so, have stripped the paper, bleached the area, now planning on giving the area a coat of anti-damp paint, before battening up and insulating with 50mm celotex (is that an excessive thickness?).

Obviously, I want to put the book shelves back, so I'd like some advice on the battening. Should I run vertical battens, and then when I come to put my shelf ledges up, attach them onto the verticals, over the top of the celotex? Or should I put horizontal studs directly to the wall, then celotex above and below that? (The span of the shelves is about 150cm, so i was going to use some sort of torsion box construction.)

Also, I'm planning on putting 6mm MDF board over the top of the celotex, rather than plasterboard. This would form the backs of the book shelves.

Thanks for thoughts and suggestions!

 

[noseall]

Dry foam fix the celotex to the wall.

Fill any remaining gaps or joints with silicone mastic forming an airtight seal.

Dry foam fix a sheet of 18mm wbp ply to the celotex. Once set supplement the foam fixing with some 100mm screws and plugs.

Then fix the shelves to the ply. I personally, am not keen on mdf.

 

[brightondiynotfan]

Thanks for the reply.

So, I'll need to screw through the celotex, into the wall, for the ply...

And shall I do the same for the shelf supports - screw through the celotex into the wall? Because presumably I'll need to go deeper than 18mm for the screws for these, as they're pretty heavy when loaded.

Cheers

 

[cmother1]

You shouldn't need to plug the shelves to the brick with the set-up suggested. The ply on its own should be plenty strong enough to hold them up (assuming you don't do something daft, like drill huge pilot holes).

I've recently solved my book storage problem by throwing most of them out. I recommend it - it's really liberating!