hi looking at insulation options and trying to make final decision.
Timberframe 215 sq metre house with 220mm stud walls, osb outside, 37.5mm insulated plasterboard for inside.
Roof has 60mm kingspan t7 outside the rafter and is cross battened to allow air under the slates.
1. Spray foam.
Originally i was very sold on the idea of spray foam insulation as it can double as an airtight layer, is easy to apply (by contractor) and can fill all cavities. having looked at a number of very negative posts here and on construct ireland have pretty much decided against this option as there are questions about condensation and the wood being too enclosed..
Cost in the region of 11 - 12 k
uValue: .16 in walls. .19 in roof
2. METAC rock wool.
the option provided by the TF company, it would need additional airtight membrane.
Cost: around 8-9 k (cant quite remember)
uvalue .16 in walls .19 in roof
3. Cellulose:
seemingly it would need to be sprayed into a closed frame wall because it is 220 thick.
cost 13 - 15 k
uvalue: cant find it right now, but it was not as good as some of the other insulations.
4. King span: good stuff but expensive
walls 200 mm K12 board
roof 60 mm K7 board x 3
cost: 19K
uvalue: .13 walls, .11 roof
5. Xtratherm rafterlock
have fitted 1 sample board, which fits stud sizes. although it is designed to squash and then expand into the gap it was a bit of work getting just 1 in and would leave smaller gaps unfilled..
2 x 100mm boards to walls and roof
cost: €13,891
uvalue: .14 wall, .11 roof (including external k7 board)
6. thermohemp
this also is sold in teh appropriate size for the studs. the question is; would it work with the osb and K7 outside it and the insulated plasterboard inside.
Cost 15,767
uvalue walls .19 roof ?
those are the options i can see at the moment.
price, effectiveness and suitability are the issues. i have also to take into account that i already have the k7 external insulation on the roof and the insulated plasterboard: and do these effect the potential benefits of some of the insulations, such as cellulose or hemp ( i.e. sealing them in so that their breathable properties are of no use).
any suggestions or opinions are welcome, my head is wrecked....
Timberframe 215 sq metre house with 220mm stud walls, osb outside, 37.5mm insulated plasterboard for inside.
Roof has 60mm kingspan t7 outside the rafter and is cross battened to allow air under the slates.
1. Spray foam.
Originally i was very sold on the idea of spray foam insulation as it can double as an airtight layer, is easy to apply (by contractor) and can fill all cavities. having looked at a number of very negative posts here and on construct ireland have pretty much decided against this option as there are questions about condensation and the wood being too enclosed..
Cost in the region of 11 - 12 k
uValue: .16 in walls. .19 in roof
2. METAC rock wool.
the option provided by the TF company, it would need additional airtight membrane.
Cost: around 8-9 k (cant quite remember)
uvalue .16 in walls .19 in roof
3. Cellulose:
seemingly it would need to be sprayed into a closed frame wall because it is 220 thick.
cost 13 - 15 k
uvalue: cant find it right now, but it was not as good as some of the other insulations.
4. King span: good stuff but expensive
walls 200 mm K12 board
roof 60 mm K7 board x 3
cost: 19K
uvalue: .13 walls, .11 roof
5. Xtratherm rafterlock
have fitted 1 sample board, which fits stud sizes. although it is designed to squash and then expand into the gap it was a bit of work getting just 1 in and would leave smaller gaps unfilled..
2 x 100mm boards to walls and roof
cost: €13,891
uvalue: .14 wall, .11 roof (including external k7 board)
6. thermohemp
this also is sold in teh appropriate size for the studs. the question is; would it work with the osb and K7 outside it and the insulated plasterboard inside.
Cost 15,767
uvalue walls .19 roof ?
those are the options i can see at the moment.
price, effectiveness and suitability are the issues. i have also to take into account that i already have the k7 external insulation on the roof and the insulated plasterboard: and do these effect the potential benefits of some of the insulations, such as cellulose or hemp ( i.e. sealing them in so that their breathable properties are of no use).
any suggestions or opinions are welcome, my head is wrecked....