Hanging interior walls with profiles and drywall, what should be considered?

Hello,

I have an old barn that I am converting into living space; the floor with underfloor heating and screed is mostly finished. Now I still have to work on the walls and ceilings.

To get them straight, I was thinking of suspending them with drywall profiles and gypsum board, since completely replastering everything, removing old plaster, etc., would be very, very time-consuming. The walls are about 18cm thick and not yet insulated from the outside, but that is planned.
If I now attach profiles and put gypsum board on them, a cavity will form between the wall and the gypsum board; is this problematic in any way?
Would it make sense to fill it with insulation material? If yes, with which one?

Thanks for your help!

Best regards
Bernd

If I now install profiles and put drywall on them, a cavity arises between the wall and the drywall. Is this problematic in any way?

Basically not, if insulation is applied from the outside. Alternatively, simply glue the drywall instead of working with profiles.

Would it make sense to fill this with insulation material? If yes, with which one?

No, because you always have the problem that moist indoor air enters the insulation and reaches the cold exterior wall. This then causes condensation problems. However, this only applies if there is no exterior insulation. If exterior insulation is added, it doesn't matter – leaving it empty also saves money.

Basically not, if the insulation is done from the outside. Alternatively, simply stick on drywall instead of working with profiles.

No, because you always have the problem that humid indoor air gets into the insulation and to the cold outer wall. Then condensation problems occur there. But this only applies if there is no external insulation. If external insulation is added later, then it doesn’t matter – not putting anything in also saves money.

So I can’t say yet exactly when the external insulation will be done, it could also be 2-3 years later than the interior work, is that then problematic? Sticking it on is somewhat difficult because the wall is already relatively uneven, at the ends adjacent to doors probably plastering is necessary because there is not enough space left from the wall to the reveal, but that shouldn’t be a problem anyway.

Do I have to consider anything when suspending the ceiling? Directly above is the roof, I want to insulate the ceiling from above, then on one side of the ceiling do I need a vapor barrier or should I rather leave it open so that moisture can escape upwards if it occurs?