tile installation question

[Tom Jones III]

Sorry about posting this to a ww'ing forum, but I don't know where else I would get an answer.

I'm going to lay tile in an upstairs bathroom. The tile is 16" travertine. I will be putting down 1/4" hardibacker over 3/4" plywood. I've got screws made for installing hardibacker to the plywood. Do I need to put thinset down over the plywood before I lay the hardibacker down? The floor is squeak free and relatively flat. There are no major cracks or tearout on the floor. I took up a small amount of tile that is being replaced and it was set on what looked like thin drywall nailed to the plywood.

[Michael Gabbay]

That's what I did. I used 3/4" Durock cement board and put thinset on the plywood and screwed the cement board to the ply. Some say don't screw directly into the joist. Make sure you stagger your seams on the subfloor and hardibacker. Also leave 1/8 - 1/4" gap on the outside walls for expansion.

Another tip that I got from a tiling contractor was to tape and mud the seams at the time you lay the tile. I did not work that well for me so next time I'll tape and mud and tile later. Let your mud (thinset) joint be wide so as not to create a speed bump.

Have fun and get a good set of knee pads! :eek:

Mike

[Kenny King]

check out John Bridge's tile forum for questions on tiling

http://johnbridge.com/vbulletin/index.php


I put my hardibacker down with thinset. I did a mortar bed for the kitchen. If I do it again, I'll go with the mortar bed. It sounds old fashioned, but it takes care of levelling the floor and really I think a great way to go... great way to go if you like mud :)
- Kenny King

[Scott Parks]

Yes, put down a mortar bed. This will take out any "dead" spots in the hardibacker, and make your floor solid. If you have any dips in your subfloor, use a floor leveler first. It will make it easier to get your tiles laid flat. If you use the hardibacker, NOT the old wonderboard (cement wrapped with fiberglass tape), you don't have to tape your seams. The taped seams make a ridge. Then it is harder to get your tiles flat. Just be sure to use acrylic modified thinset to lay your tiles, or add it to your mix.

[Russ Massery]

I agree with scott. Most certainly with a 1/4 square notched trowel.This is one place you don't want to skimp.

[Roy Wall]

Agree with all the above....

I retiled our Mudroom last year and thinset below the backer board too....

[Steve Aiken]

Not to say that you haven't already gotten good advice, but you will get excellent advice from the tile-setting professionals at http://johnbridge.com/vbulletin/index.php

I would have gone horribly wrong without their help.

Steve

[Phil Maddox]

Your subfloor thickness should be a minimum of 1 1/4" thick, which leaves you a bit shy at 1". How about moving up to 1/2" concrete backer board like Durock? The 1/4" won't hurt your height that much and will add some stiffness, something you need for tile that large.

Contrary to what many think, the larger the tile, the MORE support it needs.

The backer board (hardi, durock or any others) should be laid into a bed of thinset mortar.

Good luck!

[Tim Burke]

I too am looking at doing my first floor tile job. My floors are already 1.125" thick throughout the house. So I just wanted to use the 1/4" hardibacker screwed to the floor.

With enough screws, is it necessary to use the thinset between the hardibacker and the current floor? My concern is for removal years from now if we ever want to do a new floor. If you use thinset, won't it make removal a royal pain?

Thanks, Tim

[Russ Massery]

Yep, You have break all the old subfloor and replace it. I've done it a few times it's no fun. right up there with taring off a roof with two layers of shingles on a 90+ degree day:(.

[Tim Burke]

Yep, You have break all the old subfloor and replace it. I've done it a few times it's no fun. right up there with taring off a roof with two layers of shingles on a 90+ degree day:(.

Looks like I'm well qualified for ridiculously difficult work :D . I tore off 25 squares, 2 layers thick, from my 2 story house during the late days of summer. I waited until I thought the hot days were past. As soon as I started, it got back into the mid 90's. It was so hot I couldn't work in the afternoon!

[Russ Massery]

Same thing happen to me at my old house. Waited till late Sept, the day I started it when back into the 90's.

[Mark Singer]

Marble and stone are best "mud set" . They are tamped innto place ond not layed over a backer.