I have a walk-in shower (no door) and was planning on using cement board for the wall floor. Do i have to use a vapour barrier behind the cement board on the would frame? If so, what kind? Simply lay the tile on the board (wall floor) with thinset? What kind of thinset? Any help would be appreciated! Thx
More info is needed. What is on the floor of the shower now? A vapor barrier is needed for and insulated exterior wall. I use 15lb felt but 6mm poly can be used also. Insulation-vapor barrier-cement board with edges and corners taped with cement board fiberglass tape and thinset. Versabond modified thinset.
I've done this more times than I can remember. As the other response said, a vapor barrier is needed for insulated walls. Wet the cement board down with a sponge before applying the tiles so that the cement board does not pull the moisture from the thinset too quickly. Use thinset, not mastic, as mastic is water-soluble and will not work for wet-area applications. Use a grooved trowel with grooves set to an appropriate depth for your tiles based on their size and material. Find the center point of the focal wall, both vertical and horizontal, draw it out on the wall with a pencil or marker, using a ruler or level to make sure the lines are straight, and work your way out in either direction. MAKE THE TILES LEVEL, DO NOT RELY ON THE SHOWER RIM TO ACT AS A GUIDE. Once you have the layout set you're better off starting from the bottom and working your way up, using spacers between tiles, than working your way down and having them slip on you. Cut the tiles with either a wetsaw or tile splitter, either can be purchased or rented at your local home depot/lowes/whatever. Make sure to factor in for the spacers when measuring. The only tiles you should need to cut are the ones along the edges. Let the thinset cure for at least 24 hours. If you're working with porous material such as natural stone, seal it to prevent the grout (dye, sand, and glue) from staining the stone. Mix the grout in a small container. Better to gradually add water than to add too much. Apply with a rubber trowel, following along with a tile sponge. You want to get the glue and residue off the surface of the tile. Dry with a rag, or they sell cheese cloth too for a follow-up if you like. Wait 72 hours or more for the grout to cure. Seal again with tile impregnating seal.
Use Hardibacker and seal the seams with tape and thinset. Use thinset to set the tile using 1/4 spacers. I have used and recommend that you use a tile sealer to seal the slate prior to grouting and to use epoxy grout. The grout is more difficult to install but requires no sealers which need to be redone at least once a year in a shower and is well worth the initial time and effort. Be sure to read and follow the directions on the grout bags to ensure a uniform color and good grout set. MT C
