Wondering if someone can advise me! I'm in the process of restoring a summer cottage built in the 1950s. About 12 years ago, new wooden paneling was installed on the exterior of the house directly onto the asbestos cement panels. Now today, there is the problem that you can't install plastic on the inside drywall after adding an additional 70 insulation on the inside. If you do, any moisture that gets in won't have a chance to escape. I see three options.
1. Remove the asbestos. (A large workload involving first carefully removing the wooden paneling in the existing layer, and then properly removing the asbestos)
2. Keep it as is, drill holes in the tongue-and-groove wall and through the asbestos to allow the moisture to dry out. (How many holes, does this really work?)
3. Keep it as is. Don't apply a PE film but add insulation and drywall as usual. (Does this really work with the drying out of moisture in the wall? Convection and diffusion through the wall?
Best regards, Christian
1. Remove the asbestos. (A large workload involving first carefully removing the wooden paneling in the existing layer, and then properly removing the asbestos)
2. Keep it as is, drill holes in the tongue-and-groove wall and through the asbestos to allow the moisture to dry out. (How many holes, does this really work?)
3. Keep it as is. Don't apply a PE film but add insulation and drywall as usual. (Does this really work with the drying out of moisture in the wall? Convection and diffusion through the wall?
Best regards, Christian
Question: Is this based on the assumption that the eternit is diffusion-tight? Otherwise, I don't understand.
I'm really not an expert on the material, but the wet eternit sheets I've seen haven't felt particularly "tight." It just soaks right through.
Another possibility is that one is worried about water condensing on the eternit, but since the temperature drop over the eternit sheet is zero (or?), I don't understand that either.
I'm really not an expert on the material, but the wet eternit sheets I've seen haven't felt particularly "tight." It just soaks right through.
Another possibility is that one is worried about water condensing on the eternit, but since the temperature drop over the eternit sheet is zero (or?), I don't understand that either.
Exactly right!
Thank you so much for your quick response!!!
The crux, however, is whether the eternit is moisture-proof or not!
I do have some loose tiles, do you think there's a way to test it? Or can it be fine without plastic on the warm part of the wall? Since I'm planning to add extra insulation on the inside, making it 140 mm thick insulation instead of the 60 cm mineral wool it was before, the conditions for moisture transport might change, right? Warm air from inside, if the eternit is moisture-proof, could condense there and cause mold on the plank-clad wall that the eternit is mounted on?
Best regards, Christian
Thank you so much for your quick response!!!
The crux, however, is whether the eternit is moisture-proof or not!
I do have some loose tiles, do you think there's a way to test it? Or can it be fine without plastic on the warm part of the wall? Since I'm planning to add extra insulation on the inside, making it 140 mm thick insulation instead of the 60 cm mineral wool it was before, the conditions for moisture transport might change, right? Warm air from inside, if the eternit is moisture-proof, could condense there and cause mold on the plank-clad wall that the eternit is mounted on?
Best regards, Christian
How fun with so many responses!! 
Wonder if there is any way to check it though!!?
It's silly to take a chance with plast! If you don't do it, what happens then. It should be that regardless of whether eternit is moisture-proof or not, the wall will contain more moisture due to moisture transport from the inside out. It will probably be difficult to dry out the wall in that way. On the other hand, there hasn't been any plast before, but then with much less insulation, of course.
Regards, Christian
Wonder if there is any way to check it though!!?
It's silly to take a chance with plast! If you don't do it, what happens then. It should be that regardless of whether eternit is moisture-proof or not, the wall will contain more moisture due to moisture transport from the inside out. It will probably be difficult to dry out the wall in that way. On the other hand, there hasn't been any plast before, but then with much less insulation, of course.
Regards, Christian
Hello!
According to a table I found tucked away, fiber cement boards have a water vapor permeability of 0.28-0.42 x 10[sup]-6[/sup]m[sup]2[/sup]/s, which is on the same level as, for example, particle board and pure wood.
If the asbestos cement sheet is 6mm, the water vapor diffusion resistance Z would be 0.006/0.28x10[sup]-6[/sup]=21.4x10[sup]3[/sup]s/m.
That's about 1/100th of the vapor diffusion resistance of plastic foil ---> Keep the asbestos!
According to a table I found tucked away, fiber cement boards have a water vapor permeability of 0.28-0.42 x 10[sup]-6[/sup]m[sup]2[/sup]/s, which is on the same level as, for example, particle board and pure wood.
If the asbestos cement sheet is 6mm, the water vapor diffusion resistance Z would be 0.006/0.28x10[sup]-6[/sup]=21.4x10[sup]3[/sup]s/m.
That's about 1/100th of the vapor diffusion resistance of plastic foil ---> Keep the asbestos!
Remove the crap.
No fun nailing when putting up paneling.
No fun nailing when putting up paneling.