Replies

1. 
   Guest_ | Jun 29, 2000 02:36am | #1

   *
   Mark,

   The best way to do it: remove existing floor coverings down to original subfloor; install 1/2" concrete board fastened properly, if you set it in thinset, put down an additional layer of underlayment between subfloor & concrete board; marble thresholds look nice as the doorway transition; take the time to do a dry layout to determine the best size for cut pieces, don't just start with a full piece in a corner somewhere; tile base generally looks better than wooden base in a bathroom; undercut jambs & casings

   Red dog

1. 
   Guest_ | Jun 30, 2000 12:23am | #2

   *Depending on the tile and the condition of substrate, I would consider a deck mud job.I would consider a deck mud job if: (1) The substrate is a bit spongy and needs to be stiffened up; (2) Is uneven in any way; and (3) Where there may be a lot of traffic.But if the substrate is in good condition, and flat, wonder board is fine.For transitions between surfacts, use a threshold.

1. 
   Guest_ | Jun 30, 2000 01:01am | #3

   *Thanks for the GREAT tips! Especially the transition and the base comments.I was somewhat unclear regarding your statement "if you set it in thinset, put down an additional layer of underlayment between subfloor & concrete board". Do you mean setting the tile in thinset or the cement board in thinset (which I've never heard of)? Additionally, what do you mean by underlayment? Do you think it's OK just to fix the concrete board to the top of the subfloor (plywood), or do I have to put something in between the concrete board and the plywood?Thanks again!!!!!

1. 
   Guest_ | Jun 30, 2000 01:35am | #4

   *Mark: I would recommend using a CPE membrane (chlorinated polyethylene) for waterproofing. I rarely see a bathroom that hasn't had an overflow from toilet or sink and if kids (up to 21) are using the bath then you are going to have splashing and/or dripping bodies.I wouldn't rely on grout sealer to protect the underlying structure from water damage. Most people don't apply it twice a year. You also get the advantage of using the CPE as an isolation membrane. There is a big difference in expansion between lumber products and the cement board/ceramic tile. I just did one where the subfloor had to be replaced and I had a joint. Two little kids would be using the bath. The bath directly under the 2nd floor already had ceiling damage. I used DalSeal TS but Nobleseal TS is about the same. (TS is for Thinset...the ONLY thing you want to use). The CPE goes over the cementboard substrate, held by thinset.I cut the CPE to go up the walls about 4". Seal the corners with caulk. The CPE has a spun polyester layer on both sides for bonding with the thinset (looks like anglehair). Don't walk around on the CPE too much before tiling or the hair balls up and comes off. Thinset your tiles to the CPE.I took a scrap, formed a pocket and poured water in it. No leaks for weeks. I use it on the sill too if the shower has a window in the wall. Michael Byrne clued me into all of this stuff at a JLC expo. There was a pretty good article in the January 1996 JLC magazine. Its on CD now. I think Byrne heads up the Tile Council of America. Try a search with google.com. (If you really want a top notch job use CPE on tub and shower enclosures and for sure on tile countertops) Thor

1. 
   Guest_ | Jun 30, 2000 12:37pm | #5

   *Mark,If you set the concrete board in thinset, don't put it on the original subfloor. If you do, the next time you need to replace this floor, for whatever reason, you will have thinset adhered all over it. In my opinion, this is not a good thing to do to your subfloor. If the subfloor is flat, ie. plywood, and structurally sound, there is no need for that thinset, just nails.Red dog

2. 
   Guest_ | Jun 30, 2000 08:53pm | #6

   *Mark,When I read Thor's post on the splashing, dripping bodies I was reminded of the time a friend had a Japanese exchange student at his house. Water was coming down through a ceiling light in the kitchen. They ran upstairs to find the student kneeling beside the bathtub and pouring water on her head with a bowl. They didn't have our version of the bathtub where she came from. With the tile floor looking like part of the whole "system" she assumed this is how it's done in America.Darrell

3. 
   Guest_ | Jul 01, 2000 06:34pm | #7

   *Mark:Going with Thors installation will definitely give you a waterproof installation, and Nobleseal TS is a great product. However, I think a standard, properly installed mortar bed will give you the protection you need. It probably should be called moisture protection and not waterproof, because it isn't, but I think it will be sufficient,unless you plan on hosing down your bathroom floor on a regular basis. If you do go with the Nobelseal(or Dalseal) over backer board it should be bonded to the sub floor with thinset and screwed or nailed appropriately.Good Luck,Dave