Hi!
A construction question that I've googled endlessly without finding an answer.
I'm going to insulate with isolinas flax insulation boards. With ecological insulation, you should have a layer inside the insulation that is 3-4 times more dense than the layer outside the insulation.
For the inner layer, I have bought isolinas air barrier paper which has a vapor diffusion resistance measure of 24x10^3 s/m (http://www.isolina.com/se/isolering-byggpapper.cfm)
And for the outer layer, byggmax wind barrier paper which is the brand Teno AC350 (http://nwp-temp.se/_teno/wp-content/uploads/2014/02/Pdb-Teno-Vindskydd-AC350.pdf) but where the only measurement for vapor diffusion resistance is 1.15 ±0.2 m (EN 1931).
How on earth do you compare them? I want to be sure that the inside is 3-4 times more dense than the outside, otherwise, I have to replace the wind barrier paper...
A construction question that I've googled endlessly without finding an answer.
I'm going to insulate with isolinas flax insulation boards. With ecological insulation, you should have a layer inside the insulation that is 3-4 times more dense than the layer outside the insulation.
For the inner layer, I have bought isolinas air barrier paper which has a vapor diffusion resistance measure of 24x10^3 s/m (http://www.isolina.com/se/isolering-byggpapper.cfm)
And for the outer layer, byggmax wind barrier paper which is the brand Teno AC350 (http://nwp-temp.se/_teno/wp-content/uploads/2014/02/Pdb-Teno-Vindskydd-AC350.pdf) but where the only measurement for vapor diffusion resistance is 1.15 ±0.2 m (EN 1931).
How on earth do you compare them? I want to be sure that the inside is 3-4 times more dense than the outside, otherwise, I have to replace the wind barrier paper...
It states that the Sd value for the Isolina paper is 0.59m
Zv for the byggmax windproof paper then becomes 1.15m/25*10^-6 = 46x10^3 s/m
http://www.fuktsakerhet.se/sv/Documents/omrakningsfaktorer.pdf
So it seems that the ratio is about 0.5 = that is, the outer layer is denser than the inner.
Zv for the byggmax windproof paper then becomes 1.15m/25*10^-6 = 46x10^3 s/m
http://www.fuktsakerhet.se/sv/Documents/omrakningsfaktorer.pdf
So it seems that the ratio is about 0.5 = that is, the outer layer is denser than the inner.
Ok, thanks! Then it was as I feared... anyone have tips on a wind barrier with an Sd value of around 0.15 m? Preferably made of paper or another natural material, it would be nice to avoid plastic but it will have to do if no alternatives exist.
(What does the Sd value refer to actually? Is it converted to the equivalent thickness of some other "standard material"?)
(What does the Sd value refer to actually? Is it converted to the equivalent thickness of some other "standard material"?)
A quick Google search:
Icopal Vesta Pro, 10x10^3 s/m, = Sd=0.25m
http://www.icopal.se/Produktsortime...ro_produktblad_monteringsanvisning_101006.pdf
The Sd value is equivalent to the thickness of air.
Icopal Vesta Pro, 10x10^3 s/m, = Sd=0.25m
http://www.icopal.se/Produktsortime...ro_produktblad_monteringsanvisning_101006.pdf
The Sd value is equivalent to the thickness of air.
Formulas were found in the link in post 2
http://www.fuktsakerhet.se/sv/Documents/omrakningsfaktorer.pdf
http://www.fuktsakerhet.se/sv/Documents/omrakningsfaktorer.pdf