It's now warm enough to begin tiling my kitchen floor. I have two
topics I'd appreciate your thoughts on. (1) Expansion joints and (2)
mortar & grout. The area to be tiled is a little over 30 feet in one
direction and 22 feet in the other. Part of the substrate is 1/2
plywood over 5/8 T&G plywood, the other is 1/2 Durock over 5/8 T&G
plywood. The support structure is 2x10s on 16" centers with no
unsupported span of more than 12 feet.
The tile is Daltile, 8 x 8 x 5/16.
I'm not thrilled about putting tile on plywood so I am also covering the
plywood in those areas that don't have Durock with an isolation membrane.
In looking a various sites I find a wide range of recommendations
recommendations for interior floor expansion joint spacing. The Tile
Council of American says no less than every 30 feet, however they caveat
that by saying that in areas where direct sunlight will occur (and it
will here) spacing them as close as 12 feet is appropriate. The
expansion joint that I'm using is Schluter's DILEX-BWS
Any thoughts on expansion joint spacing? Obviously for aesthetic
reasons fewer is better, but the appearance of a cracked floor trumps all.
I'm in a remote area so supplies are difficult to get. Home Depot is a
couple of hour drive but I can get their Custom mortar there. They have
several grades of mortar. So far I've used their VersaBond mortar to
bond Durock to plywood and plan to use it to put the isolation membrane
down also. My question is what to use to bond tile. Can I continue to
use VersaBond or should I step up to their FlexBond mortar?
Also, grout is a big issue. I'll be using a very dark, almost black
grout and although I don't expect the floor to be wet I am concerned
about efflorescence and what to use for grout. Is Custom brand acceptable?