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Anybody have any experience installing new floor tile over old? Specifically, what are the TCA Handbook recommendations TR711, TR712 and TR713? I need to bid a job of tile over tile with crack isolation. The old tile is 1″ hexagon mosaic in a full mortar bed.
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Mike, I have completed many installations of this type. I'd like to take a shot at answering you, but I'm afraid I don't understand your question. What is it, exactly, that you'd like to know?
You make reference to the TCA Handbook so I guess you are familiar with it, but you question the installation methods shown. The methods shown are minimum specifications pertinent to renovation work.
Would you please elaborate?
*Rich,I wondered if anyone out there had particular experience in installing tile over tile, and how they handled it. I did not have a TCA handbook handy so I wondered what those specific recommendations say. I believe they deal with tile over tile. Nowhere do I question these installation methods. I point out that, in this particular situation, I need crack isolation. I was thinking about using NobleSeal CIS over the entire floor, but the Noble company's literature suggests consulting those specific recommendations of the TCA Handbook before using their product. How have you handled this particular situation?
*Mike, I think you have at least two options here. One, install a 'slip sheet' over the existing tile. Float a mud setting bed over this. Set tile with thinset. The slip sheet could be NobleSeal, not bonded to the existing floor. I think that may be too expensive for a residential floor. Rather, use 4 mil poly, or 15# felt.Two, scarify existing tile, sweep and vacuum, apply trowel-applied liquid membrane (Custom's Semco, or other), set tile with acrylic modified thinset. Just be sure to leave the floor as flat as possible, don't chip or grind holes into the floor.As the 1" tile is probably porcelian, you shouldn't have to use acid or detergent to clean the floor. (Porcelian is highly impermeable. Therefore, it would not be susceptible to bond-breaking absorbtion of fats and greases.)The installation methods TR711; 712; 713, do not make reference to a crack suppression membrane. TR711 is a general catch-all list of requirements and specifications. TR712 details interior floors, but again it only is a list of requirements. TR713 details interior wall installations only.TR711 and TR712 do make reference to other installation methods, notably F111 and F141.F111 and F141 do make reference to a cleavage membrane (same as slip sheet), but they also call for a full mortar bed (1-1/4 to 2" T). This may be a big problem, since you have cab heights, thresholds, etc to concern yourself with. My option #1 shown above assumes a mortar bed thickness of The only difference between F111 and F141 is that F111 details installations over concrete subfloors, F141 details installations over wood subfloors.I make reference to the handbook quite often, yet I am always amused that it consistently makes reference to local building practices. In other words, much of what determines the use of an installation method is...your own experience.For my company, I have a zero callback policy. I will not 'cheap-out' during installation; it may come back to haunt me. Therefore, I use methods and techniques that help to ensure achievement of my policy. I have used the options listed above repeatedly. I am quite satisfied with the results I have gotten.BTW: I did not mean that you question the methods in the handbook; I assumed you had a handbook, so I did not understand why you wanted further information on the methods.As TCA is composed of over 50 member companies, your tile showroom could get you a copy for free just by asking a member company's dist. rep. But, you have to ask.
*If you can't get one from your distributor, the TCA handbook may be ordered by calling (864) 646-8453. It's three bucks plus shipping.
*Mike:It looks like Rich, as usual,pretty well has it covered. I know that the Schleuter(sp?)company makes a crack isolation product but I dont have any experience with it. I would go with the slip sheet and mortar bed that Rich uses.Good Luck...Dave
*Rich,What about NobleSeal (Probably TS since I need to buy a couple of rolls for another job) applied to the roughed up tile with flexible thinset? Then the new tile directly to that? This would be fine over concrete or wood, but I have never done it over existing tile. Cost is not a factor, there are only 35 sq ft. to the job. I don't especially want to increase the thickness much.Thanks,Mike
*Mike, now that you mention it, I do recall using NobleSeal TS for crack suppression membrane over existing tile floors. I didn't like the way the jobs went, but, lo and behold, no callbacks and the owners were delighted with the installation. I did use acrylic modified thinset to bond the NobleSeal to the existing tile.I became friends with one of the owners, so I am at their home periodically. Five years later, no problem.