Hardi-Backer vs Wonderboard vs Durock

[MikeBob]

Snipe,
"I do understand why you use mastic for mosaic. I just don't trust the stuff. The guy who taught me how to lay tile told me that a lot of the rip-out and repairs he's done were because the tile-setter used mastic.'

Back in the 40- late 50s they did not really have a thin set mortar for walls that stuck and worked, so on walls they used mastic, floors were set in thick set mortar, about an 1"+ base of it. A lot of time with chicken wire laid in it like concrete mesh then set the floor tile in it.

[who]

Most mastic these days is bright white, just fine for the clear glass mosaics. 

Sure there have been about a bazillion failures, but I'd bet most had to do with installer error.  I've ripped out tons of showers and tub surrounds that were a wet moldy mess.  Mastic doesnt belong in a wet area.  Todays products are a water based glue which re-emulsifies when moisture wicks through the grout, or the caulk fails.
Up until a few years ago, greenboard was the standard of cheap builders and handy hacks who didnt know any better... Some wet mastic trapped behind the tile layer would eventually turn that greenboard into a moldy mess too.

Like I said earlier, I wont use it often. Most of my tile work gets thinset, but it does work great on tiny tiles in a dry area like a backsplash.  I have no worries about it failing.  

The stuff from the 40s straight up until the 80's was a solvent based mastic..  Good stuff, but over time it seemed to get really hard and brittle and would lose it's bond to tile.  I've demo'ed plenty where you could flick the tile off the wall with a fudge .

[MikeBob]

Most mastic these days is bright white, just fine for the clear glass mosaics. 

Sure there have been about a bazillion failures, but I'd bet most had to do with installer error.  I've ripped out tons of showers and tub surrounds that were a wet moldy mess.  Mastic doesnt belong in a wet area.  Todays products are a water based glue which re-emulsifies when moisture wicks through the grout, or the caulk fails.
Up until a few years ago, greenboard was the standard of cheap builders and handy hacks who didnt know any better... Some wet mastic trapped behind the tile layer would eventually turn that greenboard into a moldy mess too.

Like I said earlier, I wont use it often. Most of my tile work gets thinset, but it does work great on tiny tiles in a dry area like a backsplash.  I have no worries about it failing.  

The stuff from the 40s straight up until the 80's was a solvent based mastic..  Good stuff, but over time it seemed to get really hard and brittle and would lose it's bond to tile.  I've demo'ed plenty where you could flick the tile off the wall with a fudge .

As a tile setter and bathroom remodler for 20 years I DITTO that.