penno

Going to do an on suite bathroom and have told the customer the power shower area will need tanking, will only cost him about £20-£30. Doesn't want it doing. I am tiling over plastered walls and have advised him that without tanking the water could go behind the tiles and create dampness resulting in damage to the area. Any advice on what i should do? I know he doesn't want it doing but i don't want it wrecked in a few months, still want my work to be first class. Told him i can't guarentee the work without tanking.