hi fellas,doing a bathroom room up in a block of flats. it's a bath/shower combi. taken all the tiles off & about 1ft above the bath where it was tiled up to,it's built out bout 1/2 inch of pure concrete so wanna build it out above as i want all the wall tiled. as it's an old block of flats the ventilation is pretty s**t & gets well steamy. should i use m/r boards with a coat of w/b agent or strictly aqua panel? can you d&d aqua panel? or should i just d&d normal boards & use a top waterproof tile adhesive?