hey there doug,

i have been laying tile now for 13 yrs. i don't suggest that anybody
use durock for anything. in a bathroom shower area i use hardi- backer
it a lot better than durock. instead of thinset use mastic its better
for walls and there is no mixing. it comes in a 1 or 3 gallon bucket.
if you have a home depot near you buy it from there. the brand name of
the mastic is custom products. its the best on the market. when using
the hardi backer just make sure that the screws are flush against the
board. and also remember that you must have the screws 8" apart from
each other too.

i hope this will help you .

bill