woha
2011-03-26 17:55:43
- #1
Hello everyone,
I want to renovate my attic, which I have already been living in. Some of the somewhat outdated paneling will also have to go. I took down the paneling in one room, and as expected, there wasn’t much insulation between the rafters (built in ’74). There are 160 rafters, between them is 6-8 cm of aluminum-coated glass wool. There is neither a vapor barrier on the room side nor an underlay membrane on the outside, so behind the glass wool you can see the tiles directly (of course on battens ;-) )...
So I went to a building materials dealer and asked for advice and offers... The largely unanimous opinion was: insulation between rafters 140 mm, with a 2 cm ventilation layer on the outside due to the missing underlay membrane, then a vapor retarder, cross battens, between these also another insulation layer, 40-50 mm, then the ceiling cladding, in my case no longer wood but drywall...
What do you think of this setup?
One idea I have is to double the rafters inward with an “old” existing panel board (1.5 cm) to be able to install 160 mm insulation and still have a ventilation layer, albeit only about 1.5 cm... Does that make sense?
Another problem I suspect is in the area of the knee wall. In my case, it is masonry. What do I do there? I cannot get my rafter insulation behind this knee wall... nor a vapor retarder (-barrier), because the wall extends between the rafters... I would now stick the vapor barrier to the wall (with this special adhesive in cartridges). Or does it only make sense if the insulation goes behind the knee wall, etc...? The problem there would be that the knee wall would have to be removed first, then something would have to be put back, and that would also be significantly more expensive... And I would basically have to do everything at once and cannot really proceed room by room and stretch it out over time and finance it more calmly...
I am grateful for any tips
Best regards
woha
I want to renovate my attic, which I have already been living in. Some of the somewhat outdated paneling will also have to go. I took down the paneling in one room, and as expected, there wasn’t much insulation between the rafters (built in ’74). There are 160 rafters, between them is 6-8 cm of aluminum-coated glass wool. There is neither a vapor barrier on the room side nor an underlay membrane on the outside, so behind the glass wool you can see the tiles directly (of course on battens ;-) )...
So I went to a building materials dealer and asked for advice and offers... The largely unanimous opinion was: insulation between rafters 140 mm, with a 2 cm ventilation layer on the outside due to the missing underlay membrane, then a vapor retarder, cross battens, between these also another insulation layer, 40-50 mm, then the ceiling cladding, in my case no longer wood but drywall...
What do you think of this setup?
One idea I have is to double the rafters inward with an “old” existing panel board (1.5 cm) to be able to install 160 mm insulation and still have a ventilation layer, albeit only about 1.5 cm... Does that make sense?
Another problem I suspect is in the area of the knee wall. In my case, it is masonry. What do I do there? I cannot get my rafter insulation behind this knee wall... nor a vapor retarder (-barrier), because the wall extends between the rafters... I would now stick the vapor barrier to the wall (with this special adhesive in cartridges). Or does it only make sense if the insulation goes behind the knee wall, etc...? The problem there would be that the knee wall would have to be removed first, then something would have to be put back, and that would also be significantly more expensive... And I would basically have to do everything at once and cannot really proceed room by room and stretch it out over time and finance it more calmly...
I am grateful for any tips
Best regards
woha