I'm doing some wall panelling for a customer and am after some advice/opinions please.
It's a large dining room that I am panelling out, I'm basically putting 25mmx50mm tile laths on the walls to straighten things up (dpc between the laths and the walls), covering it all in MR MDF then adding some strips of MDF to form the panels.
It's an old place with solid walls, they all seem dry but one of them is an external wall. I was going to put a coat of external varnish on the back of the MDF in case there was any damp but then I wondered if there was any stick on foil you could buy which might do the trick? Of course then I think well should I just put some Kingspan in the cavity which would also act as insulation?
The walls are really bent so in places there is a 75mm cavity between the back of the MDF and wall. As it's a solid wall I guess it should be allowed to breath although at some point it has been refinished with modern plaster.
I just wondered if people thought it was best to leave a cavity and just varnish the back of the MDF or if I should put some maybe 20mm Kingspan or other foil type insulation in the cavity keeping it off the wall?
I don't want to cause any problems with condensation etc in the cavity.
I originally wanted to build a stud wall with insulation in and a breathable membrane etc but the customer didn't want to lose the space.
Don't suggest using something other than MDF as it's already bought
Any advice appreciated.
Thanks, Doug