I purchased a sheet of 4’x8′ – 1/2″ exterior grade plywood and asked Home Depot to cut it to size for me.  I painted the underside and edges for a little extra protection and then screwed it into my framing.  Next step was to cut the hardie backer board down to size.

I applied a bit of thinset in between the plywood and backer board for extra adhesion.

FYI – it’s been in the mid to high 90’s here for wayyyyy to long.  A friend of my suggested that I put the thinset pail in a bucket of water to keep it cooler than the air temps.  It worked perfect!!!  Never dried up on the top or edges of the thinset pail.  Thanks Sherry!!  I actually had this pre-mixed thinset left over from tiling my bathroom shower (over a year ago).  That is one advantage to purchasing pre-mixed.  You don’t have any waste.

I used the hardie backer screws to attached the backer board to the plywood and clamped the seam down to dry.

My last 5 tiles!!!  Planning on trimming it out and grouting this weekend!