Adhesive for concrete board and tile

[Fishboy]

I was watching one of those DIY channels the other day and they were laying floor tile. They used an adhesive like Liquid Nails to put the concrete board down on the floor before they screwed it down. This got me wondering why I use thinset to lay concrete board, and why I don't try something like one of these new adhesives. After all, aren't you just trying to get the tile or concrete board to adhere to the underlying surface?

I'm much interested in your opinion, particularly in using something like this for an outdoor application.

Aloha pumehana,
Brian and Mary
Lynnwood, WA\Discovery Harbour

[hotinhawaii]

I've done it both ways, liquid nails and thinset. I have never had a problem either way. I suspect that thinset fills any gaps between the subfloor and backer board better, but once it is screwed down and the tile is installed, will tiny gaps make a difference anyway? The liquid nails approach is faster and easier in my opinion. I did encounter a problem once when I used a non-modified thinset (without any latex additive). The backer board sucked the moisture out of the thinset before it set up and months later the tiles all popped off. If using thinset, either use the modified or add the latex additive. Another lesson learned.

[riverwolf]

I have done a lot of tile work, and strongly recommend the modified thin set over any glue especially with ext. work. Some people will use the glues for easy [ I didn't say lazy ] application for small areas on walls, but thinset is the best route especially on horizontal or large wall area i.e. showers, foyers...
Also best to tape the joints as well.

riverwolf

[Rob Tucker]

If you are laying any tile or cement backboard into thinset the tile or backerboard should not be dry when set. It should be wet to avoid sucking the moisture from the thinset.

[Fishboy]

I appreciate all your comments and I wouldn't likely use a glue to mount tile, but what about mastic? I've never used it myself, but I've seen mastic used in bathroom wall tile application. When is it appropriate to use that?

Also, what about using epoxy to mount things ONTO a tile surface? Such as a tile soap dish or other fixture. I've use that epoxy that comes in a cylinder about the size of a roll of quarters with the hardener wrapped around the resin to apply a tile soap dish onto the tile wall of my shower enclosure. It worked SO much better than any other adhesive, and it bonds absolutely.

Aloha pumehana,
Brian and Mary
Lynnwood, WA\Discovery Harbour

[Carey]

I have used both mastic & modified thinset on my floor projects.... mastic takes a very long time to set (up to a week), & seems to have had more voids (hollow when tapped) in setting my 16" tiles than thinset.... (and of course, no pre-wetting tiles & floor with mastic....) all were set the same way... so...

None of the floors are in high traffic, & all are holding down, just the mastic areas have a hollow sound near some of the centers of the tiles...

I now only use the modified thinset - cost & cure time are the main reasons, and none of the mosaic work was done with mastic., including the wall mosaics I have done in the ohana shower room.... mainly because I was using the Schulte system for our ADA roll in shower area