Polystyrene tiles between rafters

Joined
18 Jan 2006
Messages
300
Reaction score
3
Location
Cumbria
Country
United Kingdom
I probably already know the answer to this question but I will ask it anyway. We had all the roof tiles replaced about five years ago and afterwards I renewed the loft insulation and boarded the loft. I also fitted 2" thick polystyrene between the rafters, the polystyrene being cut into tiles that wedged between the rafters, totally covering the membrane. I did this as I was going to use the loft for a train layout, however that never happened but I left the the tiles in place.

Recently I have been hearing that this it is not a good idea to enclose the rafters in any way as this can prevent the loft breathing and the tiles can trap moisture between them and the rafters which can lead to rot in the long term. As a result, I have removed a few tiles to check the state of the rafters underneath. The rafters seem dry so far but should I remove them all now to prevent any problems in the future?
 
Sponsored Links
Joined
15 Nov 2005
Messages
77,166
Reaction score
4,790
Location
Crossgates, Europe
Country
Cook Islands
is there roofing felt under the tiles?
If not, the gap will have ventilation.

Modern practice is to use "breathable membrane" which is slightly porous, I suppose a bit like gore-tex


the real problem is with sprayed-on foam, which sticks to the roof timbers and holds damp.
 
Joined
18 Jan 2006
Messages
300
Reaction score
3
Location
Cumbria
Country
United Kingdom
Yes, I have a breathable membrane. The polystyrene is effectively up against the membrane.
 
Sponsored Links
Top