Traditional cement backer boards and fiber boards require some type of moisture barrier to be.
Tiling a shower wall over drywall.
Sand the wall with 80 to 120 grit sandpaper on an.
While it probably does a decent job the drywall above the surround may suffer from water that sprays up or from moisture that accumulates on the drywall.
Can i put backer board over drywall for shower tiling.
You can rough up the painted surface which allows the mastic or thin set mortar especially those designed for painted drywall to adhere.
The wedi board wedi shower system includes special bonding agents referred to as wedi caulk though is much more than caulk that waterproofs the seams in the corners as well as the joints where the 3 5 board pieces join together.
Your shower surround keeps water from coming into contact with the wall behind it.