I’m bidding on a job to do a retile in a small bathroom. They want the old tile removed and the new tile set so it lines up to the wood floor in the hallway. This means removing the 2 1/2 inches of cement and tile down to the planking and then building it back up to receive a thinset application and 6×6 ceramic tiles.
What should I use on top of the planking to bring it up to the height I need? I was thinking about sheets of plywood or strand board – laid in contrasting directions until I reach my desired height. This would add rigidity and wouldn’t require me floating another mud job.
Any thoughts?
Replies
Two layers of 3/4" plywood (glued, screwed, tatooed) plus 1/2" cement backer board (thinsetted and screwed) plus thinset and tile should get you pretty close and should provide a quality job. Don't forget to charge for the time and disposal cost of getting that old mud job out of there!
Al Mollitor, Sharon MA
Thanks. Just to clarify... I'm following on the plywood. Then you're saying to set a layer of cement board in thinset? Or are you saying to screw the cement board to the plywood and then thinset and tile?
Appreciate the time and the reminder on the removal costs.
I usually thinset the tile directly to AC plywood, because it seems I never have enough room for plywood and backer board. But if you have room, many people think backer board is very important on the floor as well as the walls. The backer board is supposed to have thinset under it to make sure it doesn't flex over low spots in the plywood. So, yes, thinset and screw the board.
Al
You should thinset your CBU to the plywood and then nail it in place. Also check the height of your toilet flange. You don't want to be to high or to low there.
My suggestion is to get involved in learning how to do a mud job.
A small bathroom is a perfect place to start. Its really not al that difficult and in my mind is the best possible tile job one can do.
For a beginner I'd recomend laying out the mud and the next day setting your tiles using thinset over the cement.....down the line when your comfortable with mud jobs you can set the tile directly into the mud the same day.
If you want info then I'd be more than happy to speak with you about different methods.
Be floored
andy
My life is my practice!
http://CLIFFORDRENOVATIONS.COM
I'm interested in doing this the best way possible. So, if floating mud is it, then I'm prepared to do that. I've built shower pans before, so I may be ready for this. The subfloor is just planking, so I'm going to have to put a layer of plywood down and then float on top of that. Assuming this works, any assistance on doing a quality job would be appreciated. As you said, this is a small space and may be the perfect place to learn.
Thanks in advance.
My house (circa 1960) has a mud job over plank flooring with just tar paper under it. So you probably don't have to waste the money on plywood if you don't want to. Just a data point, plywood might help that floor from cracking down the line.
MERC
Be sure to use felt paper over the cdx so the wood doesn't suck the liquid out of the mud. Also use a liquid latex additive rather than water.
Level a cpl of 3/4x3/4" sticks down the length of the bathroom (using some of the mud to lift the low ends of the sticks) and make a screed a few inches shorter than the room so you can slide it back and forth forcing the mud into place( a straight 1x4 works). After you screed the mud over the floor (over the sticks) pull out the sticks carefully and take your trowel and fill in the voids where the sticks were.
Be sure to use wire lathe as well over the felt paper.
Next day: thinset down your tiles after sweeping the mud job clean.
Have fun
Be well
andyMy life is my practice!
http://CLIFFORDRENOVATIONS.COM
Thanks. Doesn't really sound so difficult. May even be less time consuming than measuring and cutting all that plywood and backerboard. We'll see. I'll give it a go. I'm assuming you use 3 parts sand to 1 part portland? Also, with the mesh, it lies directly on the felt paper? And, how do you account for the toilet drain assemby when screeing? I guess I just scree up to it and then after it and trowel the section in between?
Do not under any circumstances, build up layers of plywood and then tile right to it. Tile and plywood expand at different rates, and the tile will crack and the bond will fail.
You do have a couple of other options, which I will list in order of my favorites;
1. Mud Job. This will be the cheapest and best quality approach. Break up the mud (it is fairly sandy and will break up easy, if it is truly mud, and not reinforced concrete) with small sledge, gloves and a 5 gal bucket. Measure the span below the floor and advise us what it is (joist size, span, plywood, etc) and see if it is suitable for tile without more plywood. Assuming you are OK, spread tar paper or poly and 3.5 diamond lathe over the floor. Establish your elevation (presumably at the door, right?) with block of wood. Allow for tile thickness and about a sixteenth for thinset. Mix up the mud (pre-bagged or 6-1 sand and portland, no additives). Spread out a pile of mud in the center of the room at the same elevation as your bloock (use a level, OK?). Spread out 2 3/4" dia pipes parallel. Put mud under then until they are level with your mud pile or your block. Fill in the space between them with mud, beat it with a wooden trowel, and keep moving down the room with your pipes, removing them and moving them, setting them, and filling in the holes. You are officially a mud man now.
2. CBU and Ply. Make the same guage block we talked about but on the deck boards. Add ply and CBU until you reach the right elevation. CBU needs to have unmodified thinset under it to help cushion the boards. Nail them to floor boards, not joists. Don't tape or thinset the seams until you tile.
3. Ditra. Add plywood to height determined by your guage block. Buy Schulter's Ditra (an eigth inch orange membrane) and thinset it to plywood; let it cure and thinset tile directly to it.
Me, I'd do a mud job.
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934
Great tips. I'll bid it for a mud job and let you know what I find when I break up the old mud. I've seen it from below, and it looks like planking with felt paper, mesh and mud. The old school way. I think I've got about 2 inches, which would be really 1 1/2 with the tile (3/8) and the thinset. But, I'll get it all out and make more accurate measurements.
Talk to you then.
Thanks again.