"Tom" wrote in message
news:wkWSa.2453$Ye.294@fed1read02...
I plan to use 12X12 granite tile for our kitchen countertops. We have
installed a 3/4 MDF top over the counters. I have since heard that Type I
mastic is not recommended over masonite, etc. Others have told me that
Kilz
as a primer or scarifying the MDF will allow the mastic to "hold" the
tiles.
Also, can the tiles be butted and grouted only in the chamfered edges or
should there be a tiny gap?

Thanks for and help.

Tom

you shouldn't use mdf. if you aren't making a mortar bed, you need a thicker
base.

you can use exterior plywood or chipboard. you then need to use 1/2" cement
board. you then tile to the cement board.

no. use the thinest spacers for granite. 1/32" i believe. use unsanded
grout.

regards,
charlie
cave creek, az