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creeve · Joined: 13 Mar 2006 Posts: 2

Hi,

I've just moved into a chalet style house that has flat roofed dormer windows. During extensive decorating I have had to remove part of the inside skin (the internal plasterboard wall) of the dorm structure and also one whole plasterboard ceiling. By doing this it revealed that there is no insulation in the dormer structure; either the walls or the "roof" space. This seems crazy and also answers the questions as to why my house is always chilly.

I can get to the dormer "roof" void (the void is only about 200mm high) from my loft.

Questions:
**Without removing any ceilings or plasterboard walls…**

- The dormers will be replaced with new structures in the next 12-14 months, however I want to insulate them now. Can anyone recommend a sensibly priced way of doing this (ceilings mainly but any wall suggestions would be appreciated)?

- I'm currently thinking about pushing fibreglass insulation into the gap, but wondered if there was any better product/method? What about polystyrene?

- Do I need to be concerned with letting the air circulate in the “roof void”?

Thanks in advance,

Chris

thescruff · Moderator Joined: 03 May 2003 Posts: 4658 Location: Bath

"Celotex" is the best product on the market but yoy need reasonable access to dut it in between the joists.

You buy it in 2400 x 1200 sheets of different thickness, then cut it with a saw or sharp knife. 50mm is probably the best bet and you can stick two layers in if you have the space.

creeve · Joined: 13 Mar 2006 Posts: 2

Hi,

Thanks for the response.

Do you know anything about the air circualtion? Celotex talk about leaving a 50mm air gap, however other people have also meantioned that the dormer roof void needs external ventilation - I currently do not have any? Should I care about this?

Chris

thescruff · Moderator Joined: 03 May 2003 Posts: 4658 Location: Bath

Haven't a clue on ventilation requirements see pm.