This is what I read on a site that sells/manufactures cellulose insulation "Cellulose has many properties that make it good as insulation. It absorbs moisture, which counteracts moisture problems and also means that vapor barriers are not needed when building"
https://icell.se/cellulosaisolering/
I wonder if they are lying!
https://icell.se/cellulosaisolering/
I wonder if they are lying!
Do you have more features than it insulates?W witten said:
Tomture61 said:
Why is it unreasonable
How does hot/cold work, are they impossible to equalize.
Water vapor has similar phenomena as above.
Warmer air can carry more water vapor.
You cannot store that much water in the insulation so that it contributes to significantly higher RH throughout the entire winter. Then the insulation would be soaking wet.
No, it's true. It can absorb moisture if exposed to it temporarily. It also manages with a vapor barrier. So it's correct.
But that doesn't mean one shouldn't have a vapor barrier.
I have no graphs to rely on, only hearsay from homeowners with cellulose insulation and no barrier in the building envelope that the humidity is better.useless said:
I guess those who say it haven't measured either.
But it goes against the purpose of the insulation, it's not in any way cheaper than, for example, mineral wool.D Daniel 109 said:
Only need to go out into my garage with 10% higher RH to feel the difference.D Daniel 109 said:
Isn't the purpose of insulation to insulate?
It also withstands moisture better and provides better soundproofing than fiberglass. Which purpose is being destroyed with a vapor barrier?
It also withstands moisture better and provides better soundproofing than fiberglass. Which purpose is being destroyed with a vapor barrier?
One advantage of cellulose insulation is its ability to absorb moisture + release moisture.D Daniel 109 said:
Why buy a more expensive material if you're not going to utilize its properties.
Why install a hardwood floor and then lay a vinyl mat on the floor (the whole floor)
The function of the vapor barrier or vapor retarder is not solely to stop moisture migration into the exterior wall but also to prevent air movements into the insulation that negatively affect it:
""
Mineral wool or cellulose fiber-based materials are commonly used as insulation material in wooden exterior walls. Due to the moisture-absorbing capacity of cellulose fibers, a vapor retarder is considered most suitable in climate shields with cellulose insulation, and it is important that the chosen wind barrier has higher vapor permeability than the vapor retarder. However, all thermal insulation materials must be protected against air movements. This means that cellulose insulation must be provided with a diffusion-open windproof layer on the outside and a vapor retarder on the inside of the insulation to achieve the highest possible insulation capacity.
""
clipped from:
https://www.traguiden.se/konstruktion/konstruktiv-utformning/stomme/vaggar/yttervaggar/
""
Mineral wool or cellulose fiber-based materials are commonly used as insulation material in wooden exterior walls. Due to the moisture-absorbing capacity of cellulose fibers, a vapor retarder is considered most suitable in climate shields with cellulose insulation, and it is important that the chosen wind barrier has higher vapor permeability than the vapor retarder. However, all thermal insulation materials must be protected against air movements. This means that cellulose insulation must be provided with a diffusion-open windproof layer on the outside and a vapor retarder on the inside of the insulation to achieve the highest possible insulation capacity.
""
clipped from:
https://www.traguiden.se/konstruktion/konstruktiv-utformning/stomme/vaggar/yttervaggar/
At the same time, cellulose insulation is denser than mineral wool.
Using wind protection on the outside of external walls is wise but not necessary for the inside.
But nothing negative, with a vapor barrier.
Using wind protection on the outside of external walls is wise but not necessary for the inside.
But nothing negative, with a vapor barrier.
To increase indoor humidity, the insulation would need to release (a lot of) water over the winter. There's probably a slight effect like this at the start of winter, just like the wooden floor dries out and creates gaps. But moisture won't be reabsorbed as long as it's warm inside and cold outside.
to address the risk of reverse moisture transport where cellulose insulation fits its purposeBut that's not the point
Why use cellulose insulation + vapor barrier
Yes, it can absorb moisture in that situation. But it's rarely a problem even with mineral wool insulation. You definitely don't need a vapor barrier in that situation.