Sheet insulation for angled roof rafters for use of loft

[Brisand]

Can someone tell me what is the best sheet insulation to use between the (angled) rafters for use of loft space? They are 100mm deep so I guess I need about 70mm deep sheet insulation. I have had suggestions of Kingspan, but my local builder's merchants only seem to stock brands:Icopal or Eco-therm. How to these products compare with Kingspan? Is there a product available, which has aluminium backing on one side (to go up against the roof lining with an air-gap) and plaster board on the inside?

Look forward to your suggestions of sheet insulation makers and suppliers.

Thank you.

 

[masona]

Can someone tell me what is the best sheet insulation to use between the (angled) rafters for use of loft space?

From what I understand if you have ceiling joists loft insulation, this would have to be removed if you're going to put up roof rafter insulation because of condensation problem so you can't have both. We did have a surveyor on here name GwaiLo who sadly left us about a year ago. If do you a search on Gwailo post's, there's plenty of information regarding roof insulation.

 

[chappers]

kingspan, celotex, ecotherm etc they're pretty much all the same.
to comply with building regs you will need to leave a 50mm air gap above the insulation and then vent your roof also building regs will require you to either fill between the rafters with 100mm of insulation and so you will need to batten out your rafters by 50mm or you can insulate between your rafters with 50mm and then use 35mm over the rafters and then your plasterboard either way you take up the same space in your room.

 

[Brisand]

kingspan, celotex, ecotherm etc they're pretty much all the same.
to comply with building regs you will need to leave a 50mm air gap above the insulation and then vent your roof also building regs will require you to either fill between the rafters with 100mm of insulation and so you will need to batten out your rafters by 50mm or you can insulate between your rafters with 50mm and then use 35mm over the rafters and then your plasterboard either way you take up the same space in your room.