insulation queries

[kilbird]

i am building a new house at the moment and really want to put the right insulation in. decided on 125mm rigid insulation on the floor and 60mm gone into the cavity walls..just wondering what to do for the rest of the house. I have a high ceiling in the living/kitchen/dining room (pitched) and was thinking of 125mm/150mm rigid between the rafters in this area...in the rooms downstairs that only have a hosrizontal ceiling over them followed by attic space put 150mm rigid insulation between the ceilign joists and 70mm thick rigid insulation between the studs in the dormer roof...only problem is builder is saying "oh I wouldn't bother with that - the fibre is as good a job...etc" I know fitting this stuff is a much harder job for them but what do you think? Is the fibre any good ? Any advice woud be apprecaited

 

[sydthebeat]

300mm of quilted roughly equates to 200mm rigid foam insulation, so tell your builder that it is not 'just as good'......

are you getting your building certified? insulation levels are part of the building regs and there are minimum standards to be met... your certifier should inform you of this.

125 under the floor is good, but 60mm in the walls is the basic minimum standard, you could do with upgrading this....

 

[kilbird]

okay..point taken about the 60mm in the walls. Problem is this is what hs gone in at this stage - is it possible to get the walls injected aswell with the polybead even though there is 60mm of the rigid insulation in the wall at this stage???? Any problems to consider with this??

 

[Carpenter]

You could dryline your walls with a Kingspan thermal board, 40mm plus 12.5mm plasterboard; I spoke to their technical department today and this is their recommendation for conventional cavity walls. For ceilings I see nothing wrong with quilt insulation between and over joists (in a cold roof)- if the ceiling is slabbed with the same thermal board, at least this way you cut out thermal bridging through the joists.