Loft Insulation

[requiem]

Hi all

I have a question, I'm planning to install foil backed insulation board (kingspan / celotex) in the rafters of my loft. I have checked the regs and they say it needs to be 50mm in depth and have a space of 50mm between the insulation board and the tiles/felting.
The question is can i just go ahead and install the boards with plaster board finishing the job of? Will i have to worry about ventilation/ moisture between the felt and the insulation board?

Thanks in advance

Untitled

• requiem
• 7 May 2012
• 1

Untitled

• requiem
• 7 May 2012
• 1

Regards

Reqs.

 

[freddiemercurystwin]

Don't know what sort of regs you were reading there but anyway. You need a 50mm air gap between any insulation and the underside of the felt. This air gap needs to be connected to the vents at the eaves and you will need to fit continuous ridge ventilation system (£££s) otherwise you will get a condensation problems and eventually your rafters will rot.

Do a search of the forum this has been posted hundreds of times before.

 

[requiem]

Thank you for the response. I have no vents at all in the eaves. Is this normal? should i have vents/ should i get them installed?

 

[requiem]

reading these forums i gather that the ventalation used to be done between the gaps in the slate tiles however the previous owner at some point got the roof retiled and felted. Should i get vents installed in the eaves to avoid possible dump etc?

 

[freddiemercurystwin]

Yes you should.