An article last year discussed how to build a custom shower pan. The author said he always used a rubber membrane but my local tile installer said that a liquid he uses is just as good and easier to install. Is this correct or should I insist on the membrane? Any experiences with this? My installer also plans to pour the pan with a cement mixture that contains stone (the kind of bagged stuff you can buy at the hardware store but the Fine Home Building article mentioned using a mixture of sand only. Any advice on the best approach?
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I just finished a shower pan, though it was slab-on-grade, so it's hard to go wrong there. I used the PVC membrane available at Home Depot and other home centers and it worked fine. Last one I did called for a hot mop, but since the guy with the sticky stuff flaked out on me, I figured I'd try out the new technology. It worked fine. Taunton has a book that clearly explains the procedure. It's called Setting Tile. Follow the author's instructions and you can't go wrong.
Now, having said all that, I just finished helping a friend replace the shower in his elderly mother's house. The original shower was made in perhaps the 1930s and was simply a plaster enclosure and a poured concrete base over a plywood subfloor. No paper, no flashing, no sealers. After all this time, it was just now rotting the subfloor. So I guess materials don't necessarily make a quality job. Workmanship does.
Good luck!
"After all this time, it was just now rotting the subfloor. So I guess materials don't necessarily make a quality job. Workmanship does. "
I second that!
The sheet membranes are definitely superior to liquid or hot mop. There is some debate as to whether the CPE membranes mentioned in the FHB article are actually superior to the PVC you can find anywhere. However, it is a very relevant point that none of that matters if it isn't installed properly.
I also recommend the book "Setting Tile" by Michael Byrne; the author moderates the Ceramic Tile forum at JLC online which is a good source of shower pan info (sorry, probably heresy to mention here!). There's a companion video or two for that book that are worth checking out too. Also pick up the latest copy of the TCA Handbook (Tile Council of America), which will have their latest detail for a shower pan installation.
Andy,
I am curious why the liquid membranes are inferior and what type of liquid they are.
I just had a polyurethane liner troweled on in a two coat process. It is made by "armorthane", the same outfit that makes spray on truck bed liners. I can still go with the sheet membrane if I have made a huge error in judgement but I don't see the problem with this system.
Any additional info would be appreciated.
thanks, karl
The liquid membranes themselves are not actually inferior. Rather, the problem lies in getting a good seal at the drain, where the two halves clamp together. I'm not familiar with the product you're describing- was it installed over the mortar bed or beneath? Most liquid waterproofing products go on top of the setting bed right before the tile, if this is the case, make sure that whatever thinset you use will be compatible with the membrane.
I've read Byrne's book. But, what's a "pre-form"?
Andy, Thanks for elaborating on liquid membranes. The product in my pan is the same material you find in polyurethane caulking like sikaflex but a less viscous(more fluid) version of it. I opted for it as it is marketed as being very elastic (unlikely to fail if the house shifts or settles) and I have used the PVC sheet liners before and found the corners to be somewhat cumbersome.
In response to your concerns about the drain, I bedded the lower half in the polyurethane, coated the perimeter of the mating surfaces and bolted it up. I then put temporary plugs in the weep holes and Bob, the armorthane guy troweled two coats over the entire presloped floor surface and ten or so inches up the wall.
After it cured for a few days I filled the pan with water and let it set for a week and no leakage appeared in the drain or in the crawlspace. I pulled the temporary plugs out of the weep holes and the pan drained all the standing water I had used to test it. The drain flange itself is entirely covered with 3/16" of polyurethane and the temporary plugs I used to protect the weep holes formed three passages for the pan liner to direct water into.
I am using three 4' by 8 1/2' granite slabs for the walls and will pack my mud bed onto the floor and tile it after fastening the slabs to the walls.
I have only done one other shower so if anyone sees any thing to look out for I would appreciate any pointers
Thanks, Karl
I'm interested in using 5' x 8' granite slabs in a shower. How are you attaching them to the walls?Thanksdeang
I have 2 granite showers in my home. The granite fabricator also made granite bases to match, textured by sand blasting I believe and routed to slope into the drain. My panels are only 7' high and are just guled in place to the backerboard. The back panel basicaly holds the sides in. The corner seams are caulked and although only a year old no problems yet.
Thanks Pete.I'll appreciate the additional info. I'll talk with a fabricator about a similar floor treatment-Deang
I used the FHB article to build a shower pan last year. Used a vinyl membrane from Home depot that worked fine. I don't know about using a concrete redi-mix as a substitute for the cement recipe in the article. I always though the aggregate in redi-mix was there for economy. This is such a small job that I would just use the recipe from the article.
The article mentions using a handful or two of small stones around the pvc drain to keep the weep holes clear. I found a small quantity of rocks from the aquarium section of the local pet store worked great.
Tim
The top ten things to remember about Shower Pans:
10. Follow the TCA Guidelines
9. Pick impervious tile to avoid staturating the tiles and mold.
8. Pick a small square or mosiac for the floor to avoid lippage.
7. Shim the CBU about 1/4" off the stud so it clears the pan
6. Seal the ends of the CBU buried in the Pan, to prevent wicking
5. Lift the CBU's about 1/2" off the pan, to prevent wicking
4. Put poly behind those CBU's
3. Use a proper 2 part clamping shower drain
2. Remember to install a pre-slope--1/4" per foot
1. Use a membrane approved by your city. LA approves Hot Mops or the PVC/CPE Variety.
Good Luck
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1927
I have always put in a pre slope, but I've yet to find a journeyman plumber who is willing to do so; nearly went to blows once with a guy who was really pig-headed about laying the 30 mil flat on the floor. Made no sense to me then and still doesn't.
Notch: i have the same sort of problem. I have found a highly recommended tile setter, and examined his finished work. It is good - very high quality.
But - he doesn't really want to put in a pre-slope. Haven't figured out how I am going to get that one done w/o a fight before he even starts work.
DonThe GlassMasterworks - If it scratches, I etch it!
Somebody left the cork out of my lunch. W.C. Fields (1880-1946)
7. Shim the CBU about 1/4" off the stud so it clears the pan
wow .. this thread is a blast from the past, huh?
anyways ... I hold my cbu's about 6 inches off the floor.
I have the rubber run up that high ... then the mesh ... and float the second layer of mortar of the mudbed up as well ... That way ... the bottom 6" or so of my pan is a little swimming pool. Plus ... I can square ... then slightly taper the very bottom ... of the walls. I like the idea of kicking the wall drips just a hir towards the drain.
Jeff Buck Construction
Artistry In Carpentry
Pittsburgh Pa