In examining a relative's storage heater, attached to the ground floor stairs in the hall, I found it was just screwed to 6mm hardboard which had begun pulling over its nails.
The 110kg heater will be re-fitted to heavy studwork into 4x4 stair posts.
What should the boxing in be made of - 6mm plywood, 12.5mm red fire plasterboard, 6mm cementboard? Jewsons wanted =A350 for 6mm cement-board (might as well use two piece of =A315 from B&Q).
Conventional 3-bed semi, boxed-in understairs. I plan on 6mm butt-n- match MDF matchboard either side of the heater, simple rail above, retaining the wallpaper further up the wall.