I want to attach a second layer of drywall to old, partly damaged and crumbling drywall, with construction adhesive. I cannot use screws only because my patch's edges do not fall on studs (the patch will be around 60" x 48" in size).
This new double-layered wall will have to support heavy tiles.
Is gluing an acceptable method to build double-layered drywall wall? Is generic construction adhesive (liquid nails) an acceptable glue for that?
I don't want to replace old drywall because in order to do it properly I'll have to cut a huge hole in a wall that has a vapour barrier and patching it properly afterwards will be very tricky.
More detail: the middle of the area in question is crumbling due to water damage (that has been dealt with, e.g. it should not happen again). However, around it is 10-20" of good drywall, which I hoped I would be able to glue a new patch of drywall to.
My tiles are around 30kg (66lbs) in total weight, and a solid drywall can support such weight in dry area.