Vapor barrier for underfloor heating in intermediate joists?

[Gri11en]

As the headline reads:

Should one or should one not put plastic under the parquet in a heated intermediate floor?

 

[MathiasS]

Yes, the floor manufacturers want this to ensure that the top and underside of the floor are equally moist (in the "same environment").

 

[Gri11en]

As I suspected....

So on top of the underfloor heating loops it's plastic, felt paper, and parquet?

But do you not need to connect/seal it with the house's (shell)plastic?

 

[MathiasS]

Yes, that's how I've done it. And no, I haven't sealed against the wall, there has to be some limit to the madness...

 

[jackass]

I have tracked the old parquet and installed underfloor heating and will now lay chipboard + felt paper + laminate on top. Should I squeeze in a plastic film between the plates and the chipboard? If so, I won't be able to glue and screw the chipboard down, only screw it, does this increase the risk of flex and creaking?
Should I skip the plastic film?
Below is an unheated (for now) basement.
Other suggestions?

 

[cecar33]

I have tracked the old parquet and installed underfloor heating, and now I am going to lay floorboards + felt paper + laminate on top. So should I squeeze in a plastic sheet between the plates and the floorboards? If I do, I won't be able to screw-glue the boards, only screw them, does this increase the risk of flexing and squeaking?
Should I skip the plastic sheet?
Below is an unheated (for now) basement.
Any other suggestions?

Why lay floorboards, do you have no supporting floor under the parquet or not tracked across the floor joists?

 

[Segge]

The plastic is just to protect the laminate flooring, so you place it on top of the floor chipboard if you need it.

 

[jackass]

Joists under the parquet. In the bends, it is wobbly, and the tracks are along the joists in some places. I don't think laminate is supportive enough. Isn't the plastic also to protect the particleboard?

 

[vojma]

Protect the spån from what???

 

[jackass]

Moisture transport. But maybe it is not affected in the slightest?
Laminate should be quite insensitive as well, but still, the recommendation is to put plastic there...

 

[Segge]

I have underfloor heating in routed 22mm chipboard. The groove is 19mm so only 3mm remains, with laminate on top without anything in between, except metal plates and plastic. But this is in the kitchen and hallway. When I do the other rooms, I will make sure there's something supporting the turns. It is the floor manufacturer who specifies if you should have plastic and the maximum surface temperature.

 

[mariatherese]

Yes, you should do it if you are to follow the flooring manufacturers' advice. I will not do it in the intermediate floor structure. If I get damage to the floor from this, I take that risk. It should be nonexistent if I examine the Mollier diagram for moist air. If I end up in a risk area, then something else is seriously wrong.

 

[MathiasS]

I suggest that it is not the humidity level itself that is the problem for the floor, but rather that the floor has different moisture content on the top and bottom sides, which could cause the floor to warp. This could also occur in an intermediate floor.

I personally have some floors that are under plastic and others that are not, and I notice no difference between them.