SubFloor (Structural):
In preparation for laying the new 12×12 glazed porcelain floor tiles (1/4″ thick), I utilized the existing 24″ on center 2×8 joists. To increase the structural capacity, I installed additional 2×8 joists to change it to 12″ on center. To increase the support (due to the original oak joists not being exactly on center) I “sistered” additional 2×8 joists onto these.
SubFloor:
- Before installing the sub-floor, I ran all my plumbing/electrical/insulation while I had easy access to the crawlspace. One this was in place I used 3/4″ T&G subfloor plywood – glued & screwed down. On top of this I placed 1/2″ thick Hardy tile backer board (Durock could have been used also). This gave me a subfloor that was now 1-1/4″ thick, supported by 2×8 joists spaced 12″o.c. Utilizing the original joists actually gave me a double joisted 2×8 every 24″ (essentially becoming a 4×8). This has resulted in a floor that feels so solid it seems like a concrete slab.
Tiling:
- Now that the subfloor was in place I could begin prepping for laying the tile. My plan was to install the tile in the entire kitchen area BEFORE the cabinets were installed. This would result in a contiguous tile floor with no adjustments needing to made for dishwasher clearances, etc. Also, since the tile is also under the cabinets, etc., there was no need to custom cut the tile to fit against the cabinets, nor have to worry about moisture, etc., getting under the cabinets into the subfloor. Thus, my tile extends from wall to wall, and the cabinets/dishwasher, fridge, stove, etc. all sit on top of a uniform, contiguous floor.
- After laying out my lines, I used Thin-Set mortar to set the 12×12 tiles in place. For tiles over 6×6 thinset mortar is recommended instead of Type 1 adhesive. The thinset mortar is easy to use. You mix it with water in a bucket and trowel it out using the proper v-notch trowel just like you would the Type 1 adhesive. The main difference is that it sets like concrete, providing a very solid base, eliminating the likelihood of the larger tiles breaking.
- After the tile had set for 24 hours, it was now time for grouting. I used a tinted sanded grout with an additive. The additive gives the grout additional adhesive strength and seals it better. The downside is that it is harder to clean the grout off the tiles during the clean-up period. The porcelain tiles we chose were somewhat textured (but glazed) which made cleaning the grout off the tile surfaces somewhat more difficult. On a smooth tile it would have been less of an issue. You need to be careful when cleaning off the excess grout that you do not overdo the grout lines themselves. Otherwise, you will “leech out” the pigment in the grout. I consider the floor grouting (with sanded/additive added grout) the most stressful part of the job.
Results: We now have a beautiful, solid kitchen floor which will stand up to anything. The advantage of a ceramic tile floor is that it is very easy to maintain and there is no wear & tear on this type of floor. The only disadvantages are that if you drop something on it, that item (if breakable) will break, and (unless you have underfloor radiant heat) the floor retains the ambient heat – which to us has not been a problem.
Next: Kitchen Cabinets and Countertop
