Looking for information on how high the vapor density in a vapor barrier should be. Can anyone here help?
The conditions are a diffusion-open wall construction with wood fiber or cellulose insulation with wind paper (type AC350) on the cold side before the air gap and panel.
In data sheets on vapor barriers from different manufacturers, I have found figures on vapor density (vapor resistance) ranging from 24000 to 140000 s/m. It feels like a large range and impact on function.
The conditions are a diffusion-open wall construction with wood fiber or cellulose insulation with wind paper (type AC350) on the cold side before the air gap and panel.
In data sheets on vapor barriers from different manufacturers, I have found figures on vapor density (vapor resistance) ranging from 24000 to 140000 s/m. It feels like a large range and impact on function.
The best answer should be to check with the manufacturer of the cellulose insulation. They may have slightly different values depending on the type of insulation, etc.J JohanN03 said:
The "warranty" also applies differently than if you start using materials that are not really adapted.
What is the brand and type of the cellulose insulation?
Why not a regular vapor barrier?
When using cellulose insulation, you should not use a vapor barrier but a vapor retarder.D Daniel 109 said:
Should and should, you can use ångbroms and then get its, as I understand, rather theoretical advantages for now. But it's not at all wrong to use cellulose in a "normal" construction instead of mineral wool.
Why?tompax said:
Because then mineral wool would have been a better option.D Daniel 109 said:
Cellulose insulation is mostly chosen when you want "controlled" moisture movement in the walls.
If one has chosen for other reasons, then one can put plastic if they want.
/ATW
You gain better control over moisture with a fuktspärr.
That can be debated... but as mentioned, if you have a tight wall, mineral wool insulates better.D Daniel 109 said:
And in old houses that are being renovated, it can be tricky if half the house is tight while the other is not.
/ATW
Why would it be a problem? The steam brake is airtight, so you don't affect the pressure by choosing it. It is so moisture-proof that you don't get any noticeable reduction of moisture inside. So why would it be better?
Member
· Västernorrland
· 12 030 posts
Better and better, if you choose natural insulations in an old house, you might not want plastic either for ideological reasons.......Now I don't know what modern vapor barriers are made of, but the alternative is the regular paper like before.......
They are made of plastic too, so ideological reasons do not justify steam brakes either.
A vapor barrier, for example from Paroc, has a vapor diffusion resistance of 3000000 s/m, so it differs significantly from a vapor brake. How this affects in practice, I do not know.
The wall I described above is for a renovation of an old house entirely without a vapor barrier.
The wall I described above is for a renovation of an old house entirely without a vapor barrier.
The steam brake I'm eyeing is made of cellulose.
https://www.isoleringsbutiken.se/isolina-luftsparrpapper
However, I can't find any scientific evidence or research on how a diffusion-open construction behaves. Sure, one can follow the manufacturers' recommendations, but it would be interesting to understand how the whole thing works and why.
https://www.isoleringsbutiken.se/isolina-luftsparrpapper
However, I can't find any scientific evidence or research on how a diffusion-open construction behaves. Sure, one can follow the manufacturers' recommendations, but it would be interesting to understand how the whole thing works and why.
Member
· Västernorrland
· 12 030 posts
I'm then putting up paper all over my house from 1900. Cheap and simple, and it's been like that before, so why should I change it. I'll use particleboard where I can, and in some exterior walls, it will be lin. I'm forced to change the panel in some places later, and it becomes so impractical with particleboard then.......