Americast tub flange and cement backerboard

[bingdude21]

Hi all,

I was wondering if someone could give me some insight on how to properly install cement backerboard with an americast tub. As some of you may know, the flange sits about an 1 inch high off the horizontal surface and it's about 1/8th of an inch thick. When butted up against the studs the thickness of the flange does not allow the cement boards to be installed plane on the walls.

My question is Does/should the cement boards over lap the flange of the tub or can the cement board be installed up to the top of the flange and the gap between the horizontal surface and the bottom of the cement board be filled in with some thinset?

Thanks in advance,

Bingdude

[Pat]

Either way will work. My choice is to apply quarter inch plywood strips to the surface of the studs to make them flush with the tub.

[Jack]

Yes about 1/4" or less from the bottom of the blange - should be in you tub installation instructions.

or can the cement board be installed up to the top of the flange

I guess you could and have the tile overlap the flange.

I don't use thinset. I use silicone.

[ameijers]

Shim the faces of the studs, or rabbet the backerboard on that edge. Yes, the backerboard needs to go over the flange- that is a major part of your waterproofing.

aem sends...