several tub surrounds with dens-shield and like it better than cement board. Easier to work with and has just as good a warranty. Also dens-shield will not absorb water and is its own vapor barrier. Follow the directions on the dens-shield. I founs using a marine urethane caulk to seal the joints works excellent. Apply the urethane to the edge of the dens-shield as you place 2 pieces together gives an exceptional waterproof seal. Can also use it along the edge of the tub to seal the dens-shield to the tub.