What I have found and read is very well explained on how to insulate exterior walls with various thicknesses and alternating vertical and horizontal insulation. For single-story houses, I have found pictures where loose fill insulation has been sprayed at a thickness of 40-50 cm on the roof. But how is it best solved when building a 1.5-story house and you need to insulate between the roof trusses on the upper floor? To get an air gap, I have seen that you attach a spacer of at least 25mm to the sides of the roof trusses and place plywood or hardboard between the trusses, which reduces the insulation thickness in the roof even more. A suggestion I have received is: When the roof trusses are installed, nail down rough sheathing or plywood as usual, then lay a 45x45 over each truss, followed by another layer of rough sheathing or plywood. This way, you have full insulation thickness in the trusses and are finished with an air gap in the roof. It might be an expensive construction, but it feels solid to me. 1200mm between the trusses, and I assume you lay the insulation horizontally. Then I have seen that some here have installed a vapor barrier and then attached the ceiling covering to the trusses. It feels like you haven't broken the thermal bridge in the trusses then? A thought I have: if you insulate with horizontal insulation between the trusses, then crosswise 45 insulation, then a vapor barrier. Then I have the wrong direction for the battens (horizontal) to attach ceiling covering like beadboard, if you then choose to frame up an installation space with vertical studs as I have seen examples of in exterior walls.
Grateful for comments or similar topics in this forum.
Grateful for comments or similar topics in this forum.
Member
· Västragötalandslän
· 151 posts
Hello!
I have the same thought as you and plan to lay oil-hardened masonite directly on the rafters and then a spacer batten of 25 mm followed by plain board, roofing felt, etc.
If anyone has another idea, please write d^_^b
I have the same thought as you and plan to lay oil-hardened masonite directly on the rafters and then a spacer batten of 25 mm followed by plain board, roofing felt, etc.
If anyone has another idea, please write d^_^b
www.thermisol.se -Climate wind...
Hi,
instead of råspont, you should use a diffusionsöppet underlagsduk. This way, you can avoid the air gap and insulate against it.
Berliner
instead of råspont, you should use a diffusionsöppet underlagsduk. This way, you can avoid the air gap and insulate against it.
Berliner
and it costs less than half + goes three times faster.
Berliner
Berliner
Member
· Västragötalandslän
· 151 posts
Hello!
I would like to build with materials that have been around for a while so that we know there won't be any problems in the future.
I will keep it open to the ridge myself so there won't be much left for the attic, but thanks anyway for the tip.d^_^b
Best regards, Alexandersson_1
I would like to build with materials that have been around for a while so that we know there won't be any problems in the future.
I will keep it open to the ridge myself so there won't be much left for the attic, but thanks anyway for the tip.d^_^b
Best regards, Alexandersson_1
Hello!
Building the air gap on top of the rafters is not a bad idea, as it avoids the hassle of installing boards from the inside. It should not be double raw board; instead, you nail masonite on top of the rafters, then 45*45 over each respective rafter, and then raw board and felt as usual.
Building the air gap on top of the rafters is not a bad idea, as it avoids the hassle of installing boards from the inside. It should not be double raw board; instead, you nail masonite on top of the rafters, then 45*45 over each respective rafter, and then raw board and felt as usual.
What do you think about the idea of adding a layer after the diff lock is installed in the ceiling to create an installation space for electricity? If you choose fiberboard to get an air gap in the rafters, is it necessary for it to be oil-hardened? The ridge should be ventilated at the gables, but should it also be ventilated between the rafters? Is there any difference if you have an open ridge or not? Although, if you have an open ridge, you might not have ventilation grilles in the gables; it's probably sealed there, right? Does anyone have tips on what items to use for ventilation between the rafters?
The ventilation between the rafters is what you create with the masonite, from the eaves up to the ridge; if you have an attic, it goes from the eaves up to the attic.
One way to create a ventilated ridge is to skip the last roof decking, then place a piece of wood upright on which you lay the ridge tiles. There are also special metal fittings for this if you find it necessary.
You get installation space when you set furring strips across the rafters; the furring strips are then used to attach the plasterboard or paneling, for that matter.
One way to create a ventilated ridge is to skip the last roof decking, then place a piece of wood upright on which you lay the ridge tiles. There are also special metal fittings for this if you find it necessary.
You get installation space when you set furring strips across the rafters; the furring strips are then used to attach the plasterboard or paneling, for that matter.
Member
· Västragötalandslän
· 151 posts
Hello!
I have read a bit more about oil-tempered Masonite, and it seems there are differing opinions on whether it should be oil-tempered or not. The oil-tempered one doesn't release moisture as well as regular Masonite. My first question then is whether regular Masonite won't become damaged by moisture and deteriorate after a few years.
What do you think?
Andreas Högfälterud you can add another layer inside the plastic and insulate, which will reduce some thermal bridges, but if it's just for electrical installation, the sparse paneling will probably suffice.
Best regards, Alexandersson_1
I have read a bit more about oil-tempered Masonite, and it seems there are differing opinions on whether it should be oil-tempered or not. The oil-tempered one doesn't release moisture as well as regular Masonite. My first question then is whether regular Masonite won't become damaged by moisture and deteriorate after a few years.
What do you think?
Andreas Högfälterud you can add another layer inside the plastic and insulate, which will reduce some thermal bridges, but if it's just for electrical installation, the sparse paneling will probably suffice.
Best regards, Alexandersson_1
I was browsing a bit at thermisol.se... Insulating the roof with foam was something new to me as well as insulating above the roof boards, does anyone have experience with that? On thermisol, they mentioned that there can be problems with ventilated attic spaces if you have a well-insulated roof. They had no air gap in the rafters on certain types, just minimal ridge ventilation, which feels strange to me. How big is the moisture problem in a ventilated attic space really? If you have it open to the ridge, you probably have few inspection hatches to check above the insulation.