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My son-in-law is planning on installing a ceramic tile floor over a slab. The carpeting was harboring too much moisture. When we lifted the carpet to check the condition of the slab, it was black. Not from mildew, but from the asphalt oils that had penetrated the concrete under the old original asphalt tiles.
There is no residue, just coloration. There is nothing to scrape. The concrete seems porous enough to grab a thinset and I think it is going to be an ok substrate.
Am I just kidding myself, or am I heading for a problem?
We plan on using a latex based thinset mixture with 1/2 x 1/2 notches. It’s a grade IV, 12″ x 12″ brazilian tile.
blue
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Cmon, someone please tell me something about this topic!
Please?!!!!
blue
*blue, I don't have much of a clue, but you could try this. I have a buddy that owns a boat load of apartments and he has used an orange based cleaner/solvent in similar situations with great success. Problem is I can't remember the name of the stuff. (if it says "Agent Orange" on the bottle it's the wrong stuff) I'm sure you could call up a flooring wholesaler and find the name. It works great, and doesn't make you silly while you use it.
*blue, I don't much of a clue, but you could try this. I have a buddy that owns a boat load of apartments and he has used an orange based cleaner/solvent in similar situations with great success. Problem is I can't remember the name of the stuff. (if it says "Agent Orange" on the bottle it's the wrong stuff) I'm sure you could call up a flooring wholesaler and find the name. It works great, and doesn't make you silly while you use it.
*Hey Blue,About 8 months ago I did a bathroom floor in tile (6" x 6"). We removed the old vinyl, which was applied right over the original early 70's linoleum. When we got all of the old flooring up, the black adhesive had stained the slab just like you said. We went ahead and installed the tile using a latex fortified thinset, and have not had a single bit of trouble. I just installed a set of doors at the same house about 2 weeks ago, and everything is fine with the bathroom floor. Just my thoughts on the matter...James DuHamel
*Blue,You probably shouldn't have a problem if it is purely discoloration. Try applying a little thinset in a corner, just a 3 inch patch. Let it cure for about 4 to 5 days. Then chip it up. If it releases VERY easily, and you see the black residue on the chiped up underside of the thinset, you need to strip the slab with somekind of Chemical. If it is hard to loosen, and the reales pattern is irregular, ie. some thinset stays, maybe some concrete comes with, some of the thin set is black, some is not, then you should have no problem. And if you do, I didn't do it, nobody saw me doit, and you can't prove anything.S
*James, your info is perfect. I would think that the tiles would already have loosened if they were going to.I know 8 months is not a lot of time, but at least I know that the thinset will grab and bind. Thanks.blue
*Good suggestion Scott.Remeber, video cameras are everywhere now!blue
*Blue,I believe there is product made by Hydroment that is specially made to increase the bond to cutback from vinyl/linoleum. Never used it, so thats all I know.Dave
*Just because i may be paranoid, does not mean that they aren't REALLY out to get me!!Sc9ott
*blue- latex additive is the ticket- sticks to practically anything- slab can't look shiny or greasy though- that means too much oil from tar- even latex enhanced thinset won't stick then. Sounds like that is not the case here...
*oh yeah I fergot- mebee you can just caulk the whole mess then take a picture and send it to good housekeeping... probably get on a DIY t.v. show that way...
*Yeah, caulk! Why didn't I think of that.maybe we'll just caulk the tiles to the floor, and caulk the joints.thanks!blue
*blue .. wen i was subbing for a building demo contractor.. we had to go in and pop all the vinyl-asbestos tiles in a bunch of low income housing units..then he gave us a solvent, which we squeegeed onto the tile adhesive (the asphaltic kind yur talkin about).. worked it in and picked it up with wet / dry vacs...got about 90 % of the mastic and what was left was a good solid base for ceramic tile
*Mike;Don't know if that's the sort of thing I'd be posting on the internet. You know subbing for a Demo contractor. I've read and learn from your posts but in my mind's eye my image of you has been deteriorated. Next you'll tell us that you sold blood at the blood bank and were a sperm donor or something. The name of the mag is Fine Homebuilding not Better Housewrecking. Ha, Just kidding.