Couple Basic Tiling Questions

fast pasquale

I refinish Hardwood floors.. so cut me a little slack.. O.k.. Im going to help my good friend tile his bathroom floor. He's got 65 sq feet and the floor now consists of linolium over luan. the adjoining 2 rooms are a hallway and a bedroom both of which are carpeted. The thresholds are both beveled metal and the bathroom floor is approx half and inch below the carpeted rooms. My questions are:
1. Can i screw the 1/4 mortar board directley to the linoleum or do i need to attach a layer of luan to the linoleum (by screwing?) so i can screw AND mortar the cement board down? ...I'm assuming that i can't use mortar onto the the linoleum to attach the cement board?
2. We are going to use 12x12 ceramic tile. What size spacers should we use??

Thanks for the patience guys

Chris Frate
Pasquale Floors

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Chris Frate
Pasquale Floors

thom

Thinset will bond to vinyl. Take a sander and remove the gloss from the vinyl first. Use the proper spacing on the screws

I use 3/16 spacers.

Mike Finley

We would rip out the luan and linoleum, that will bring me to a 3/4 height difference which is where I would need to be. We would thinset and screw down 1/4 tile underlayment. I wouldn't tile directly to lino, which also eliminates using Ditra to solve the height problem unfortunately. 12x12s we use 1/8 grout lines.

Rich Turley

Chris,

Luan and vinyl under tile is a recipe for disaster. Take it out.

Screws attatch the CBU, not thinset. The thinset is there to fill any voids. What is under the luan?

Rich

JoeBergess

I agree with Mike & Rich. Take out the luan and the vinyl. It will make for a better job, overall. Plus you won't have as much of a height difference in your doorways.

And to repeat Rich's comment (hope ya don't mind Rich ), what's under the luan?

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Joe

reveivl

Luan and vinyl out, is my vote. Check your deflections to make sure the structure is suitable for tile and that you have enough ply so there is no deflection between the joists, then unmodified under the cbu and modified for the tile, good luck.

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Tmrrptr

I'll go w luan and vinyl out...
What IS under the luan underlayment?
Screw the cbu down, maybe w a shot of const adhesive.
1/8" for 12" tiles ? You guys are GOODer 'n me!
My bet goes w 1/4 or 3/8.
It's the quality of tile that determines grout joint, not best wishes or spacers. and I don't use spacers, anyway.
r

reveivl

The purpose of the cbu is to de-couple the tile installation from the wood floor, so you don't WANT to bond the cbu to the wood. You use unmodified thinset under the cbu to fill voids not to 'stick' the cbu to the wood. Construction adhesive will not do this, and is messy as heck in the bargain.

This de-coupling that you are trying to achieve is the reason that you want to screw the cbu down to the plywood, NOT the joists, too.

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bjg5240

I personally don't like thinset under the hardi-backer or tile board. I find that you can sometimes hear a "cracking" sound when you walk on it. Originally, the manufacturer recommended thinset & roofing nails to secure the tile board. Correct or not, we now always install the board with construction adhesive & screws. I have NEVER had a single call back for tile movement or cracking. As far a the spacer size, that is your preference. I like the smaller the better, but with 12 & 16" tile most people ask for 1/4" or 3/8". Good luck!

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Tmrrptr

OK Rev, I have always "stuck it all together."

Your method makes good/better sense.

I am NOT too old to change.
r

reveivl

Tmrrptr, me too, I hope!

I once took the contract of pulling out and replacing the tile in a walk-in cooler set on particle board that had failed big-time, they couldn't turn it off, (the cooler), and they were working till midnight every night. Took me a week of testing in a small fridge I had (had to take the beer out first), to find something that would set up over night, tried all kinds of things, modified, unmodified, mortar, mastic, you name it, finally wound up with construction adhesive! Didn't guarantee it, due to the temperature I was forced to do it in, but that was years ago now, and it hasn't failed yet.

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From where does knowledge come? If you need to know what is in a box, you could ask someone (not reliable), you could pray, (not useful), you can consult with the scripture (not helpful) or you could open the box (science)