Ceramic Tile / Underlayment idiot

[Greg]

In our kitchen, we want to put ceramic tiles on top of cement board underlayment.

I removed carpet from the kitchen floor (yeah, carpet!). Underneath are pieces of original vinyl flooring (partial removal?) and what appears to be two different types of adhesive (or other material) - one is black, the other is yellowish. Both are solid enough where removal will require lots of muscle. Below everything is 5/8" plywood subfloor. The home was built in 1957.

Is the black stuff possibly mastic? Asbestos?

Could I leave the existing junk on the floor, use a leveling material to even out the floor, and screw the underlayment on? Or should I scrape it off and try to get down to the plywood subfloor before putting on the underlayment? If so, how to remove?

Thanks for any help.

[Jeff Cochran]

Provided it's bonded well, yes. And personally, I would.

Jeff

[donald girod]

Is cement board over 5/8 plywood subfloor stiff enough for ceramic tile? Certainly the 5/8" plywood is pretty flexible, and I'm not sure how good a bond there is going to be between the cement board and the hacked and leveled base.

[Tim Connelly]

May contain asbestos.

5/8 plywood with tile backer is not an acceptable substrate for ceramic tile. And who knows how your floor is built. Limited details = limited advice.

[Tim Connelly]

More 'expert' advice, Spitter?

You'd think that when the subject line indicates they were asking _you_ directly, you'd at least have a decent reply...

[Greg]

Thanks for the feedback.

Upon closer inspection, the original vinyl floor covering has not been removed. It's covered by the black and yellow stuff. It's mostly intact, except in places around the edges, where it's very brittle and breaks right off.

What are the consequences of exceeding the maximum allowable deflection? Also, other than using screws in the cement boards, what else can be done to ensure proper bonding?

Thanks again.

[davefr]

Fix your deflection problem or choose another, more forgiving, flooring surface. Maybe a high end vinyl that has a tile like pattern.

If you still want tile, upgrade the floor's structure and consider skipping the backing sheets and float a continuous bed of mortar to be used as the tiles base.

Doing things the right way if often the most cost effective.

['nuther Bob]

Me too. Consider the possibility of asbestos, the best thing to do is leave it alone. Asbestos fibers (dust, residue) are the issue... not some asbestos buried under a new layer of floor.

Bob

[philby]

Stay away from mastic. A modified thinset is far superior in strength and durability.

If in doubt, go to any tile forum and ask the experts.

Here's a couple.

[James Keene]

Go back and read Connelly's replies.. Too bad for you if you're using google to read news posts. Looks like No-Archive -yes for Connelly..

[jeffc]

bullshit on the internet and trying to put other people down constantly to

Whatever. Go away now.

[mike]

WOW, Handyman Wars.....Cool!

jeffc wrote:

[philby]

Why do you lie? Backerboard manufacturers say to use Type I Organic Mastic OR Modified Thinset. They don't recommend one over the other (The exception being Hardibacker. They recommend THINSET). It's dishonest of you to suggest otherwise simply to help support your argument. The discussion here is about what's best.

Shit-fer-brains??? Fuck off newbie??? How old are you? Perhaps you should have spent some of that 30 years expanding your vocabulary. Or maybe working on you maturity level. Next you'll be pointing out my spelling mistakes.

I know guys with a good deal more experience than you have and I wouldn't let them tile my backsplash. I think you'd fit into that category nicely.

It's enough for me that these posts will be written into the archives at Google and anyone searching this subject for decades to come will see you for what you are.

This thread is turning into a spectacle, so unless there is some overwhelming reason to post again, I'll let you rant to yourself.

[god]

I DO KNOW EVERYTHING. What do you want to know?

God