I am looking for a bit of advice on how to insulate my roof between the rafters. As a bit of background my loft has previously been used for storage and we are about to put some walls up so I can put a desk there. The intention is that we will also have a radiator in the room. The loft already has a good layer of insulation beneath the floor.
The roof is tiled with a thick felt behind the tiles. There is ventilation at the apex of the roof and also down at the eaves. I got a deal on some Knauf Earthwool Flexible Slab (50mm) insulation so figured we could put that up prior to putting gyproc on. I have a few questions:
1. Should I place the insulation directly against the felt or do I need some type of membrane between the two?
2. My rafters are 95mm so there will be around 45mm excess by the time I place the insulation in. That means I need to pull the insulation tight against the roof. My plan was to install screws into the rafters then wrap twine in a zig zag pattern between the rafters to pull the insulation boards onto the roof. Does that sound reasonable?
3. My plan was to still leave the ventilation gap at the apex of the roof and also to keep a gap down at the bottom of the eaves as I assume the ventilation there for a reason. Is that the correct approach?
Thanks in advance. Hopefully my approach isn't total nonsense.
The roof is tiled with a thick felt behind the tiles. There is ventilation at the apex of the roof and also down at the eaves. I got a deal on some Knauf Earthwool Flexible Slab (50mm) insulation so figured we could put that up prior to putting gyproc on. I have a few questions:
1. Should I place the insulation directly against the felt or do I need some type of membrane between the two?
2. My rafters are 95mm so there will be around 45mm excess by the time I place the insulation in. That means I need to pull the insulation tight against the roof. My plan was to install screws into the rafters then wrap twine in a zig zag pattern between the rafters to pull the insulation boards onto the roof. Does that sound reasonable?
3. My plan was to still leave the ventilation gap at the apex of the roof and also to keep a gap down at the bottom of the eaves as I assume the ventilation there for a reason. Is that the correct approach?
Thanks in advance. Hopefully my approach isn't total nonsense.