jimrutherford.com 1990-2016
Home Improvement:
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Large-Format Tile

Floor

FInally after flattening the floor, we are able to put down the Ditra crack-isolation membrane and 12 X 24 inch floor tiles.  Because the tiles are so large, I was worried about  “lippage” - where a tile is noticably higher than an adjacent tile.  To eliminate that, we used something called the “Tuscan Leveling System”. 
The Tuscan Leveling System pieces are seen here.  There’s a white plastic “T-strap” and a red plastic reusable cap that are put on with a special tool to create a tension that pulls adjacent tiles into vertical alignment. 
...and into the half-bath.  Note the threshold of cut tile that makes the pattern centered in the bath.  One of the joints running with the threshold will be a “soft joint” of matching caulk instead of grout so that the floor can have some minor movement without cracking.
Hasty escape by Ruby over the ungrouted tile floor down the hall...
First step is to put down the Ditra from Schluter Systems.  This crack-isolation membrane works by forming columns of mortar that support the tile, but allow some small amount of lateral movement so that the tile doesn’t crack when the floor underneath shifts.  Installation is as simple as cutting with a utility knife, embedding in a fresh layer of thinset, and then rolling it with a rental linoleum roller makes it pretty foolproof.
To the left, you can see one of the right angle floor lasers that we used to maintain consistent joints down the hallway and across the whole kitchen.  These right angle lasers are an absolute must have for DIY tiling. Above is the hallway half-bath after fitting in all those tiles that Joe (Shown standing in the left picture) had cut and labeled.  Two people made this way less tedious.
Next step is grouting and we had selected a cementitious dark grout made by Tec.  Above is how it looked before removing the residue in the final wash.  The result was blotchy.  There were areas that were practically white.  Maybe I washed the pigment particles out? 
If you tension too hard, the strap breaks, so it takes a certain amount of getting used to .
Whatever was the cause, it was unacceptable.  We ripped it all out in a few hours with a Fein multimaster.  It’s painful to undo progress, but it was a great move.
Instead, we decided to go with an epoxy grout from Laticrete called Spectralock. In this picture, I’m mixing all of the needed powder parts together in order to get complete color uniformity across all of the batches.  Then I’ll scoop them back into the cartons while weighing to be sure that I have consistent results. 
Each of these cartons must be added to a another coupld of liquids to make a taffy-like grout that needs to be forced into the joints.
Once mixed, you get about 20 minutes to use the grout as it is on a one-way trip to hardening.  Mixing it periodically does nothing to elongate the working time like it would with cement-based grout. This is really hard work!
After an initial washing and cure, we used a floor machine (handy!) to scrub the last traces of epoxy from the tile faces.
The hard work pays off with perfect results and no detectable transition between batches.  I could do abut 50 square feet a night and the resulting floor looks as if done professionally in one shot.  The fact that we have a stain-proof kitchen floor is a bonus. 
I don’t know why I didn;’t take any pictures of putting the Ditra down, although it was particularly exciting.  We used a non-modified mortar since plywood bonding is not needed. The 75 pound linoleum roller is in the foreground and it made a real difference in getting full contact of the fleece lining of the Ditra into the fresh mortar.
We had evaluated several alternative patterns and orientations for the 12 by 24 inch tile.  In the end, we decided that the “staggered” approach in the bottom right picture above was the best.  If we put it down across the width of the kitchen, it magically lined up with the two aisles on either side of the island.