Not sure of your US products but you could use a rubberised tile adhesive, this should stay flexible in the cement sheet joint. Good luck.
We have installed 1/2"cement board on tub walls after stripping it to the studs(plastic vapor barrier installed behind cement board. Rather than attempt to handle the weight of one piece of cement board we installed two pieces on each wall(top and bottom). Despite all our attempts to get the wall flat prior to installing (house was built in 1906) the cement board surface is not completely planar/flat. Is there a joint material that we can trowel on to fill the cement board joints and low points? We intend to install 1/4" thick Swanstone tub surround on the backer board with recommended adhesive after sealing the backer board.
Not sure of your US products but you could use a rubberised tile adhesive, this should stay flexible in the cement sheet joint. Good luck.
A good edge takes a little sweat!!
I'm not clear on how this solves my problem. The wall is not flat so when the Swanstone surround gets installed there will be areas not adequately supported. Are you suggesting that the rubberized tile adhesive be used in place of the recommended Swanstone adhesive as an alternate adhesive with that has gap filling properties?