My husband is making bookshelves to go in our chimney alcove, but we can't attach anything to the back wall as it has a 52mm soundproofing 'soundstop' board on it, so we have to rely on using the sides of the alcove only. The alcove is 86 cm wide. Any suggestions as to how he can do this so our shelves don't sag. He want to make it out of thick MDF so we can paint it white. Could we attach a rear batten using extra strong adhesive such as 'pink grip'?
Thank you for your help.