hello everyone!
I wondered if could ask some advice, what would you do?
our ceilings in bedrooms are both sloped and flat.
we will leave the purlins showing, but insulate the rafters and the put matchboard cladding back up as it was...
my partner, from work, has loads of the thin foil "sandwich" insulation that's equivalent apparently of 100mm of celotex. so for that reason were using it on the sloped parts, and then one the flat ceiling sections in the middle of the roof ive gone with STEICO flex 360 from mike wye between the joists with VCL membranes etc then the matchboard cladding.
I'm hoping that the flat areas done in a breathable way with breathable materials will be enough to negate that non breathable foil insulation stuff... there is still a small gap behind the foil so the vented eaves can hopefully vent up into the loft space above th flat ceiling...
so my questions are:
1) do you think having the breathable area of flat ceiling will be enough if the foil sloped areas aren't breathable?
2) how would you go about finishing / detailing / attaching the foil around the purlins etc - I felt that the foil insulation should be made as continuous and air tight as possible - we've been told to use airtightness tape from mike wye over the VCL membrane but not much point in getting that bit perfect if the foil layer isn't "sealed"
my partner and the chap / friend who's fitting the foil both seem to think it doesn't really matter about the air tightness as the whole house I unlikely to be very "airtight" altho we are plastering in eco cork lime and then lime skim, I doubt it will be very draft free being a welsh slate house -
at present the foil is just "butted up" to the purlins with counter battens ontop, what would you do?
I wondered if could ask some advice, what would you do?
our ceilings in bedrooms are both sloped and flat.
we will leave the purlins showing, but insulate the rafters and the put matchboard cladding back up as it was...
my partner, from work, has loads of the thin foil "sandwich" insulation that's equivalent apparently of 100mm of celotex. so for that reason were using it on the sloped parts, and then one the flat ceiling sections in the middle of the roof ive gone with STEICO flex 360 from mike wye between the joists with VCL membranes etc then the matchboard cladding.
I'm hoping that the flat areas done in a breathable way with breathable materials will be enough to negate that non breathable foil insulation stuff... there is still a small gap behind the foil so the vented eaves can hopefully vent up into the loft space above th flat ceiling...
so my questions are:
1) do you think having the breathable area of flat ceiling will be enough if the foil sloped areas aren't breathable?
2) how would you go about finishing / detailing / attaching the foil around the purlins etc - I felt that the foil insulation should be made as continuous and air tight as possible - we've been told to use airtightness tape from mike wye over the VCL membrane but not much point in getting that bit perfect if the foil layer isn't "sealed"
my partner and the chap / friend who's fitting the foil both seem to think it doesn't really matter about the air tightness as the whole house I unlikely to be very "airtight" altho we are plastering in eco cork lime and then lime skim, I doubt it will be very draft free being a welsh slate house -
at present the foil is just "butted up" to the purlins with counter battens ontop, what would you do?