Replies

1. 
   Brian_HBK&BB | Dec 10, 2001 05:34am | #1

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   Check out Michael Byrne's forum on the JLC (www.jlconline.com). Use the search function and you'll find just about all the info you need on shower pans/subfloors... including a link to an article on the subject. Floating the preslope is not that difficult because you can use screed strips around the edges. Still, it's harder than the typical DIY project. Make sure you're plumber has done a few of these, and that he checks it overnight for water tightness.

   Good luck,
   Brian

1. 
   AndyL | Dec 10, 2001 06:49am | #2

   *Look at Issue FHB Issue #141, "Installing a Leakproof Shower Pan" by Tom Meehan. Also pick up a copy of Michael Byrne's book, "Setting Tile" (Taunton Press) and the most recent TCA Handbook (www.tileusa.com) along with the corresponding ANSI spec.It is essential that the pan and membrane be installed according to spec, if the installation is to last and not leak.Andy

1. 
   Scooter_ | Dec 10, 2001 08:50pm | #3

   *Cutawood, You are out of your league here. Stop. Slow down. Take a deep breath, and do this right. If you have to ask how to do it, you shouldn't be doing it, unless you have the considerable time it takes to learn how to do a shower pan. This could take a week or two.There are 6 layers in a shower pan. From the subfloor up they are:1. Roofing Cement2. 15 lbs felt3. Expanded metal lathe4. Sloped subfloor dry pack deck mud, mixed about 6 parts sand to 1 part portland cement with latex additive as the liquid. 1/4" per foot slope from the drain. It is very thin at the center like 1/4" to 1/2", just up to the lip of the drain. Do not cover the weep holes!!! How thick is it? As thick as the 1/4" per foot slope makes it. I chalk or use a sharpie pen to designate the end of the slope. I use float strips (make 'em or buy 'em) to screed the slope with a straight edge and a wooden float to finish the slope.5. Shower pan membrane, either CPE or hot mop. Out here in LA, no tilesetter does the waterproofing, and subs it out to guys in Toyota Trucks with a hot mop kettle in the back. $150. Membrane should go up the walls at least 2" above curb, and up and over the curb as well.6. Another sloped layer of dry pack deck mud with another piece of diamond lathe. Cover weep holes with crushed rock. Float it using the same method to finished height using your tile a guage.Two Dittos on Michael Byrnes's book and his 3 videos. The book is very up to date, and the videos are not, but the videos are very much worth watching. The only updates the videos would have would be some new materials, like diamond lathe instead of the poultry wire he uses, and the use of laser leveling.I would also order the TCA Tile Handbook , which has some nice cutaways of shower pans, and the Tile Council's specs on how to make them (thickness, materials, etc).You can order both the book, the videos, and the handbooks from Mikes Web site which is:http://www.jlconline.com/forums/tile/Please do not take this as criticism, but under no circumstances do you use any CBU on the floor of a shower. This is all deck mud. You can use CBU's on the walls of the shower but hold them up about 1/4" from the shower pan membrane (or they will wick water up the CBU) and apply a trowel on waterproofing on to the CBU surface. There are spec details on this in the TCA Handbook.Good, luck.

1. 
   Mark_McDonnell | Dec 10, 2001 08:56pm | #4

   *Cutawood,I'd take it a step further and hire Scooter.Or someone with his skills and knowledge.

1. 
   carl_wilk | Dec 11, 2001 06:40pm | #5

   *Scooter: what type of waterproofing do you use on the CBU? Would using plastic behind the CBU be just as good given that the goal is to prevent moisture from reaching the wall cavity?

2. 
   Scooter_ | Dec 11, 2001 08:05pm | #6

   *Waterproofing behind the CBU on the wall:The CBU like all masonry products wicks water. Tiles are not waterproof, and water will get through the tile and/or grout to the CBU. Hopefully because it is verticle, the water just glides down the CBU to the pan membrane and out the weep holes in the drain. But in heavy use showers, or showers where the grout was not packed very tight and sealed, water will get to the CBU and may wick onto the studs or framing members, so the CBU needs to be waterproofed.Two basic types: For occasional use showers, I would use at least 4 mil plastic behind the CBU, or 15lb tar paper stapled to the studs. There is a new product called Aquabar 500 that is sorta neat that is tar paper sandwiched in two layers of kraft paper. Much sturdier than regular felt and rated to 30lbs. Twice the expense.For heavy use showers, I would apply a trowel on waterproofing mixture on top of the CBU from Nobel (although there are other brands). Lay down some goop, fold in some fabric, and lay down some more goop. Its fairly thin and takes up about 1/16th of an inch. Takes less than an hour to do a shower.

3. 
   Mongo_ | Dec 11, 2001 08:29pm | #7

   *Cutawooda, Do reference both the JLC article and the recent article that was in FHB. Both have very good information. Couple those two pieces with Scooter's info and you pretty much have all the info you need.Scooter, excellent posts. Superb. Thorough, easy to follow, and accurate. My only differences in technique are that I recommend running the membrane a minimum of about 4-6" above the curb. Also, when holding the CBU for the wall tiles high to prevent wicking, I like to hold it about a quarter to half-inch higher than the top face of the finished floor tile. The wall tile can then hang off the bottom of the CBU and the wall/floor joint can be filled with backer rod and then caulked.Cutawooda, Scooter gave you great advice. Read and heed. Be careful and be thorough in your installation. Screw it up and it's an expensive bear to repair.

2. 
   cutawooda35 | Dec 11, 2001 08:37pm | #8

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   I am having a plumber come and lay my shower pan membrane. (he offered) but I still have the problem of putting the dry mix in the bottom. How hard is this to do. I plan on laying the tile myself and I and dont want to pay a tile guy to come and just do that.
   Also, when the membrane gets laid over the shower threshold, what goes after that? Do you lay hardi backer on top of the membrane and then tile over that?
   How high do you build up the dry mix?
   Thanks for ay replies!
   cutawooda35