I found some messages about 3 years old about building up a slab under tile while searching in the FHB forum. And since it looks like this topic hasn’t been visited in a while I wonder if anyone cares to weigh in on the following topic:
I want to build up my slab under a tile floor. I’d like to go with two layers of 1/2″ backer board, installed with thinset, then the tile. This would give me almost enough height to match my existing hardwood floor which is installed on sleepers and plywood over the slab.
Having limited experience in laying tile (3 floors, 2 showers over 20 years) Floating a mortar bed does not sound too appealing to me
I’ve used 1/4″ backer board over slab and under tile in the bath around 3 years ago and no problems. I used no fasteners and it is holding up great. I’m a little leary about the two layers of backer board but figure it will work. Does anyone have any experience and/or recommendations in this particular type of installation.
Replies
Your solution seem like it would work, but having put backer board down over plywood subflooring in pior jobs, it seems like lots of work to make sure both layers of backer board are in thin set and screwed down according to the fasterner schedule. I don't think I would be so concerned about putting down a mud job before using thin set to put the tiles on top of it. I watched a couple of pros do that in my house when it was built and they used sticks of the correct height (an inch and a half to match height to the wood floor) every 36 inches or so and screed to that height. When they were done, they went back and pulled the sticks and filled in the holes. They also used expanded steel mesh in the bed to give additional strength. When they put down the bed, I noticed that the mix was very dry, I suppose to minimize shrinkage and cracking. The bed was down about three days before they thin set tile on it. The job is now 12 years old and still hasn't given any problems.
Good luck..
dennis,
thanks for the reply,
Since I posted I've even thought of possibly tapcon down 3/4"plywood, then 1/2" backer board...
Your mortar bed solution makes it sound pretty easy.
What exactly is the medium, is it just regular block laying mortar? i.e. like quikcrete? or some other thinset type compound.
Go and ask about bed mud on JLC's tile section of their forum. You will get the right advice there about what to use. I don't think it is much else beyond coarse sand and portland cement, mixed very stiff, but check there. Some call it drypack.
Don't hesitate to do the subbase this way. A little diamond mesh, some screed sticks, shovel, wheelbarrow, hoe, mix, trowel, and your mix, and you are done. You will congratulate yourself.
Micro,
thanks for the tip.
I just got back from posting in JLC.