Fasteners hold it down, thinset holds it up, or so the saying goes :-)

[Tileworks]

Famous words they are, aren't they?

I was thinking about this line the other day after doing a remodel that was absolute murder. Okay, not murder, but I really really hate a tough tear out.

As a rule, I pull up everything down to the wood. This most recent floor was linoleum over peel-n-stick tiles over ancient 6x6 purplish ugly tiles over roofing felt over plywood. I think every single layer was glued down, even the roofing paper to the plywood. This was a total mess.

Once the lino and peel/stick was up, I noticed brittle pieces of the purple ugly stuff where the stove was, probably due to heat from the oven. They started to come up with little effort, until I got about 2 feet into the room that is.

It was painful, but I removed it all. In this situation it had to.

But then I got to thinking... does it really _have_ to in every situation?

Assume that everything was so bonded, that the floor looked at me and my scraper and said to me "bring it on, boy".

Since most other people here subscribe to the theory that un-modified thinset should go under CBU so that no bond actually occurs, and there's that good ol saying "thinset holds it up, fasteners hold it down", then why bother tearing out floors that don't want to come up?

And to take this a step further, let's say that we have only perimeter glued linoleum over plywood. Who cares if the linoleum isn't well bonded if those who support the un-modified thinset under CBU theory believe that we don't want a bond anyway?

I for my part, will continue to rip this stuff up, but I am simply curious.

- Bob

[muskymike]

Hi Bob, I don't think there's too many that will go over all that flooring. I think it's the feeling of starting fresh. Besides the money people are going to pay for a job we want it to last a long long time and satarting fresh we know it's done right.

[John Bridge]

Well, I don't know who off hand, but at least a couple of the backerboard companies will allow you to go over hard linoleum and peel and stick tiles.

[Dog paws]

Tiling over perimeter glued vinyl is a recipe for failure. Your vinyl/CBU/tile sandwich will become a floating floor.

[chukar8]

I think thats an excellent question,though a perimeter bonded sheetvinyl comes up easily,not all floors do. If were not trying to bond(which we arn't with unmodified) it seems well bonded and stable floors should be able to stay down????????I think though that we need to know what kind of subfloor is under the sheetgoods, or tile, or whatever it is.

[MHI]

Originally Posted by Dog paws

Tiling over perimeter glued vinyl is a recipe for failure. Your vinyl/CBU/tile sandwich will become a floating floor.

Michael, You forget about the nails holding it down?

I always like to tear everything out and start fresh, whenever possible.

Will it work going over old layers? Maybe, maybe not. Is it worth the risk? Only you can decide for yourself.

[Dog paws]

Matt, maybe screws will hold it down, I don't know. Perimeter glued vinyl will act like a slip sheet. Once the subloor starts moving, the board and tile are on there own. Unfortunately, I've had first hand experience with CBU over per. glued.
I'm in agreement with you and the rest of the folks. Why take a chance. Rip it all up.

[glen]

And after it was all ripped out what was left? Black cut back residue on the subfloor? I explain to my customers this way I can remove the well bonded vinyl (asbestos) tile and then scrape away at the tar paper for the next week and then theres still the cut back residue on the subflloor. I say leave the vinyl and cutback tar paper well bonded intact and use a thinset for the backer board thats rated to adhere to vinyl. I dont use hardi backer not saying anyone does. Lol maybe if contractors realized how much it absobed moisture it probably doesnt matter what thinset goes under it because it will get wicked away and then become you guessed it worthless . If I install 1/4 in wonderboard I will use rated for plywood thinset over yes concrete plywood and then bump it up to a spec for cut back adhesive residue vinyl etc. I understand that you used perimiter sheet goods only as an exaple.

[MHI]

Since when is cutback and vinyl installed right on the subfloor? From what I have seen, a layer of 1/4 luan or similar was installed for the sheet vinyl. Under the 1/4 luan, which is very flexable, may be voids that will cause movement. The movement wouldn't be a problem with vinyl, but will be with tile.

[glen]

Some older homes have the vinyl level with the hardwood. Conduit right under the 5/8 sleepers and another subfloor. Sometimes they sand the top other times its tar paper all cut back. Luan and masonite is an auto ripout.