mikev
2015-06-01 12:54:00
- #1
Hello,
I have a roof without full boarding, so rafters, a cross battens on top, and directly the roof tiles on that. Since last winter I had up to 10cm!!! of fast wind-driven snow under the roof, I now want to seal/insulate my roof. And if I do it anyway, I would like to convert the gained space into a living area in the future.
One of the few options, without having to completely redo the roof covering, according to my information, is insulation using sprayed foam insulation.
I have two different offers for this.
Offer 1 - VonWaldIso
Installing a fleece layer between the rafters, then foaming between the rafters with polyurethane rigid foam - 32kg/m³
Offer 2 - Stocker
Installing a foil between the rafters, then foaming between the rafters with Icynene foam (Smartisol) - layer about twice as thick as the PU offer
Due to the double layer thickness of the Icynene insulation, it would achieve about the same insulation effect as the polyurethane insulation.
Both companies also recommend insulating the gable walls with foam. The gable walls are, like the rest of the house, made of 28cm Durisol masonry (these are formwork stones made of mineralized wood chips), in front of it a ventilated Eternit facade.
The costs are also about the same for both variants.
Now the question for me is which system is more suitable for my needs. PU is closed-cell, therefore absolutely water-, vapor- and airtight. A vapor barrier/retarder could therefore be omitted with further expansion.
Icynene foams are vapor open but according to the manufacturer waterproof. Would I then have to proceed as with, for example, insulation with trapped fleece and install a vapor barrier/retarder with further expansion? Or can I also continue directly with battens/drywall there?
My gut feeling would tend towards PU insulation, but I cannot really justify it; however, when I read up I somehow got the feeling that it would be the better option. Since facts/real experiences are certainly better advisors than (my) gut feeling, I would appreciate your opinion.
Best regards Mike
I have a roof without full boarding, so rafters, a cross battens on top, and directly the roof tiles on that. Since last winter I had up to 10cm!!! of fast wind-driven snow under the roof, I now want to seal/insulate my roof. And if I do it anyway, I would like to convert the gained space into a living area in the future.
One of the few options, without having to completely redo the roof covering, according to my information, is insulation using sprayed foam insulation.
I have two different offers for this.
Offer 1 - VonWaldIso
Installing a fleece layer between the rafters, then foaming between the rafters with polyurethane rigid foam - 32kg/m³
Offer 2 - Stocker
Installing a foil between the rafters, then foaming between the rafters with Icynene foam (Smartisol) - layer about twice as thick as the PU offer
Due to the double layer thickness of the Icynene insulation, it would achieve about the same insulation effect as the polyurethane insulation.
Both companies also recommend insulating the gable walls with foam. The gable walls are, like the rest of the house, made of 28cm Durisol masonry (these are formwork stones made of mineralized wood chips), in front of it a ventilated Eternit facade.
The costs are also about the same for both variants.
Now the question for me is which system is more suitable for my needs. PU is closed-cell, therefore absolutely water-, vapor- and airtight. A vapor barrier/retarder could therefore be omitted with further expansion.
Icynene foams are vapor open but according to the manufacturer waterproof. Would I then have to proceed as with, for example, insulation with trapped fleece and install a vapor barrier/retarder with further expansion? Or can I also continue directly with battens/drywall there?
My gut feeling would tend towards PU insulation, but I cannot really justify it; however, when I read up I somehow got the feeling that it would be the better option. Since facts/real experiences are certainly better advisors than (my) gut feeling, I would appreciate your opinion.
Best regards Mike