We had builders here who constructed a new floor structure in part of the house. It's a question of a wooden floor structure between the basement and the entry level.
There is plastic in the basement ceiling. Inside this, there is insulation with moisture/condensation. It doesn't feel good. The construction also has plastic close to the parquet floor, where there is underfloor heating.
It might be that moisture is entering through small holes and gaps in the lower plastic.
Should I cut larger holes in the plastic to allow circulation of the damp air? Should I replace the plastic with something non-tight, should I ensure it dries up and then try to install completely tight plastic in the basement ceiling? Finally, I will install sparse boards and drywall in the basement ceiling.
What do you think?
There is plastic in the basement ceiling. Inside this, there is insulation with moisture/condensation. It doesn't feel good. The construction also has plastic close to the parquet floor, where there is underfloor heating.
It might be that moisture is entering through small holes and gaps in the lower plastic.
Should I cut larger holes in the plastic to allow circulation of the damp air? Should I replace the plastic with something non-tight, should I ensure it dries up and then try to install completely tight plastic in the basement ceiling? Finally, I will install sparse boards and drywall in the basement ceiling.
What do you think?
Member
· Norrbotten
· 3 390 posts
Plastic on both the top and bottom sides of a floor structure? It's never good to trap moisture. And why is there plastic under the parquet floor on a wooden joist structure? Do you have a very damp cellar that will "supply" moisture from below? Otherwise, I would undoubtedly remove the plastic where I could reach. Ideally, I would have wished for the plastic to be removed under the parquet, but since this is hardly possible, you'll have to take it from the underside.
Now there's some faulty thinking here...
Generally, you have plastic closest to the warm side of a construction. In your case, it's likely just beneath the parquet floor on the entrance level.
If you have plastic on the ceiling in the basement and it's a bit colder there or not heated at all, it will obviously end up just like it has with you. Warm cozy air carrying a lot of moisture reaches the colder plastic and deposits water until a new equilibrium is achieved.
I can't think of a situation where it's correct to have plastic on the ceiling in the basement. That film should be REMOVED. Whoever built it seems to have thought of attic floors but didn't understand why things are done the way they are. Sealing layer on the WARM side, then it will be correct...
Plastic under the parquet on the entrance level will never be wrong and is often something that the floor manufacturer requires.
Generally, you have plastic closest to the warm side of a construction. In your case, it's likely just beneath the parquet floor on the entrance level.
If you have plastic on the ceiling in the basement and it's a bit colder there or not heated at all, it will obviously end up just like it has with you. Warm cozy air carrying a lot of moisture reaches the colder plastic and deposits water until a new equilibrium is achieved.
I can't think of a situation where it's correct to have plastic on the ceiling in the basement. That film should be REMOVED. Whoever built it seems to have thought of attic floors but didn't understand why things are done the way they are. Sealing layer on the WARM side, then it will be correct...
Plastic under the parquet on the entrance level will never be wrong and is often something that the floor manufacturer requires.
Member
· Norrbotten
· 3 390 posts
Yes, you have plastic closest to the warm side, but against a floor, there is essentially no vapor pressure which is why I don't see the benefit of this, do you see any? Wouldn't it actually be best to remove all the plastic in a wooden joist above a basement?
On wooden floors with underfloor heating http://ama.byggtjanst.se/Default.aspx?articleId=126&Typ=AmaNytt
Here, moisture-barrier systems are mentioned for slab-on-grade, which feels natural, but on wooden joists above a basement, I only see potential problems with plastic and very little benefit.
On wooden floors with underfloor heating http://ama.byggtjanst.se/Default.aspx?articleId=126&Typ=AmaNytt
Here, moisture-barrier systems are mentioned for slab-on-grade, which feels natural, but on wooden joists above a basement, I only see potential problems with plastic and very little benefit.
As I understand it, floor manufacturers always request plastic directly under wooden floors for the reason that they want the same climate on the top and underside of the floor (to avoid crooked floors). In an intermediate floor, I think it will be that way anyway, but as I perceive it, this is the reason why they explicitly require this regardless of the situation.
I am not saying that one should do as in the 40s, but in my flooring, there is a black wind barrier (type) so that the wood shavings don't fall down. It seems to work well, but indeed wood shavings are likely better at absorbing and releasing any moisture than modern mineral or glass wool is.