Replies

1. 
   WayneL5 | Jan 21, 2006 06:43pm | #1

   I depends on how uneven you are talking about.  Generally, yes, you can use thinset to make up the difference if you use a fairly coarse trowel and the mix has some body to it.

   An alternative is pourable self leveling compound.  They work well.  Then you would not need cement board.

2. 
   sully13 | Jan 21, 2006 06:59pm | #2

   HandyDan

   I would not worry about placing cement backer board on the floor.  We use a self leveling mortar which can be applied from feather edge to 1" thick, made by TEC.  Best stuff in the world.  Doesn't need any re-mesh; just tape or caulk any open seam and dam around doors and HVAC openings to prevent it from flowing where you don't want it to go.  Your supplier should have an installation vid or booklet.  We usually have 3 guys to pour it, but it can be done with 2.  You just need to make sure that you keep the pour going once you start.  We start in the lowest spot and work from there, building it up until we have about 1/4" depth at the highest spot.  Make sure to roll a coat of the sealer on to the floor first and let it dry.  I think you can start tiling in a few hours after it has been poured, though we wait 12-24.  We use this on concrete and plywood floors.  It is more expensive, but it gives us an almost dead level floor with minimal effort.

   sully

3. 
   FastEddie | Jan 21, 2006 07:00pm | #3

   Cement board used on the floor needs a bed of mortar or thinset.  Mix it a little thin so that it will flow when you tighten the screws.  Spread a fairly thin coat with a notched trowel.  The idea is for the thinset to fill any small voids ... it's not supposed to elevate the backer off the floor like a piece of tile.

    

    

   "When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it."  T. Roosevelt

1. 
   IdahoDon | Jan 22, 2006 04:11am | #4

   Ditto what FastEddie said. 

   And make up any unevenness when you set the tiles.

2. 
   user-88093 | Jan 23, 2006 09:11pm | #5

   thanks to all for your invaluable input.  I used highly viscous thinset to great effect.

   Handy Dan