I have to hang a corner wall unit, one face will go onto an exterior block wall, the other face will go onto a plasterboard "eggbox' wall, two layers of plasterboard with cardboard inside, the studs are miles apart so I cannot screw into them. Would umbrella anchors do the job (if I use several), or would I be better off fitting battens behind the unit, both top and bottom using the umbrella fasteners and then screwing into them thru the unit? I would reinforce the battens with glue between...
Hanging wall units
Hanging wall units