Adding insulation internally on wooden floor

[valjn]

I have installed a 25mm wood floor over 24m2.
Now I am going to divide the room and add extra insulation inside (I have 3 exterior walls).
There is a 10mm gap around for the floor to be able to move.
Can I safely screw my studs for the additional insulation into the floor or only attach to the wall (considering the floor's movement)?
In the middle wall, I have no choice but to screw, but I am uncertain about the outer part.

 

[valjn]

No one knows what happens when you lock the floor?

 

[jeppe_L]

Screw it into the wall! Otherwise, it will definitely lift itself =(

 

[petersson79]

Yes, if you screw it into the floor, it doesn't matter if you have a 10 cm margin of movement, it's fixed!

 

[valjn]

Talked tonight with an old builder, he says he has always screwed into the floor without problems. However, he only screwed one screw per meter.
Of those I've talked to, most say to screw into the floor, nothing will happen. (However, some are completely against it) But I would gladly take more of your good advice.

 

[valjn]

Perhaps I should mention that the floor is screwed into joists 600mm cc and not floating.

 

[jeppe_L]

Aha..thought it was floating!

But you might as well screw into the wall anyway...there's really no reason to screw into the floor. However, the wall you are going to erect should of course be attached to the floor.

 

[valjn]

What makes it a bit more difficult to attach to the wall is that I will insert an insulation board (15mm fasadboard) behind the studs to avoid a thermal bridge. Then insulate with 45mm insulation.

 

[jeppe_L]

Aha, can you install the fasadboard on the wall first, the same way you would with plasterboard?

 

[valjn]

It is possible, but the wall is not completely straight, so there may be a lot of adjusting with the studs. Had you then thought of using nail plugs through the stud and the facade board or?

 

[klaskarlsson]

If the floor is already screwed, then there are no problems, but why do you have a 10 mm gap around "so the floor can move"? The floor is still fixed

If the floor is already screwed, it doesn't matter to screw it again... A floating floor can move several centimeters and therefore you should have a movement allowance at the walls so that the pressure against the walls doesn't cause it to rise in the middle. I don't understand what the person who said he only screwed in a screw per meter and that it would be okay meant!!? Then it's rather better to fix the floor properly—either you have a floating floor with movement allowance or it's fixed. But in practice, it probably often doesn't cause any problems anyway

If the floor is floating, you can theoretically screw in the middle so the floor at least has a movement allowance in either direction—but you should avoid screwing along the walls, or wedging the floor there since it can't move—and risks rising in the middle.

/K