Waterproofing/Tiling Our New Shower Stall

I would use the waterproofing membrane on the walls.

Your tiler though should be able to advise what is best but in my opinion the tile mastic is not sufficient as waterproofing.

I must tell you though that I come from Australia where building codes and common practices are most likely different to where you are from!

Thanks for the advice, although this is not the answer I was hoping for as it just means more $$$$. Arghh! Thank you though. I appreciate your opinion.

Is the cement backer board up already?

If not, you can put poly sheeting on first, overlapping the edge of the tub and then the board. You also need to tape the seams between the cement board pieces with alkali-resistant fiberglass tape and thinset. Be sure to use a powdered thinset rather than anything premixed.

Sorry, but another question. Are you talking about Redguard or Ditra? Did you do the shower pan, etc, or are you just doing the tiling?

I want to tile part of my existing shower stall at the bottom half aprox. About 3 or 4 feet from the shower base. The drain area is sound, What steps do I take to waterproof the walls and srounding lower half from water leakage.
The lower part that I retile will be a different pattern and design, to make motre attractive looking
Thanks for help

Meagan,
Use a single pre-molded shower pan with drain center hole. The base will have a top 1/2" lip. The wall covering overlaps the lip before tiling. The most economical installation using a ferro cement board (Wonderboard, Hardiboard, etc.) as a wall surround is easiest with a Quickset pre-mix filler. This is done to create a level scratch coat surface at joints and corners. After the scratch coat is cured and smoothed out, trowel on an even mastic sealer adhesive layer for setting the tile into the mastic. Let that set as per the manufacturer recommended curing time before using a final grout between the tiles.

If you are using an acrylic type scratch coat for sealer and adhesive, some tilers will fill the tile spaces at the same time. This can make cleanup difficult as if the tile is not set first, it will move if not set properly. The cement surround will be impervious to leaks if done adequately. Even if polysheet is used behind the boards on the wall and a leak or sweating does occur, the polysheet will still force water to migrate to below the pan floor. Surface finish sealing is most important to make sure a grout seal is properly cured and maintained. Nm

You can also use Roofing Felt to provide a Water Proof seal behind your backer board. Just make sure you overlap it by at least a quarter and if you are still worried use some Roofing cement to "glue" the felt together. It's a LOT cheaper than the membrane.

I agree if you have a leftover roll of felt on hand, otherwise 6 mil polysheet costs less than puchasing a roll of 15 lb felt. Hope this helps. Nm

Personally I wouldn't worry about it. The cement board is impervious to water. Seal joints with thin set and nylon tape and you will be fine. The tile and grout will repel water, the cement board will not absorb any water that should get through a grout joint. Wasn't long ago that we were using drywall as a backerboard, now we are using impervious cement board and someone wants to add a plastic liner behind that. What's next, waterproofing the plastic.

As far a Holmes on Homes and other TV shows, remember that these are TV productions, put out for you entertainment, not necessarly you education. Some are about as realistic as the reality shows and the old time westerns. Guess who sponsers the production, the same people who make the expensive orange stuff.

Harold is correct, you do not need any membrane at all if you used cement board, wonderboard or Hardibacker board, etc... The orange stoff at Home Depot is for flooring on concrete. Concrete floors will always crack and the orange stuff allows a very small amount of slip to absorb the cracks movement, not needed for a shower stall. Use modified thinset to set your tiles. I also recommend a epoxy stain proof grout.