The month of bath and vanity flooring: Part 4, tips for laying tile

BFF and I learned a lot of tips about laying floor tile from this adventure, and she'd done it once before albeit with small tiles. It was all new to me other than the wall mosaics we did a couple of years ago, so I watched and listened. Here are the main takeaways from our experience:

• Label your tiles before setting them

When the tiles were all cut and laid out where they would be once they were set, BFF devised a system of labeling each one. Because we didn't do a traditional layout, picking them up would be like disassembling a giant jigsaw puzzle and having to solve it all over again.

She assigned each tile a number and a letter to correspond with the section of the project where it belonged so we wouldn't be looking at all the triangles, for example, and thinking, "Maybe this goes in the bathroom? Or does it fit in the hall vanity?" Once you spread the thin set, even if you're working in small sections, you don't want to be wasting time trying to figure these things out.

She used masking tape to label the top of each tile and included arrows and numbers indicating which tile each side adjoined. Since some of the tile shapes were similar, this made the process go very quickly. She even added arrows showing whether the tile adjoined a wall, a cabinet, or the bathtub.

• Make sure your subfloor and underlayment are level

We made the mistake of assuming the subfloor was level. Despite using the backer board underlayment, we discovered after the tiles were set in the master vanity there was a variation in height between two of the tiles right in the middle of the floor. If we had checked whether the floor was level before we started setting the tiles, we wouldn't have had to pry up those two tiles the next day, cut one of them, scrape off the hardened thin set under them, cut another tile and reset them.

All it would have taken to check whether the floor was level would have been to lay a straight edge across each set of adjoining tiles to make sure the straight edge didn't teeter. As it was, BFF was able to level the tiles by supporting them underneath with screws under opposite corners of the tile, adjusting the height from one end of the tile to the other before applying the thin set.

• Properly prepare the tiles, backer board and thin set

Wipe down the backs of the tiles with a damp cloth and do the same to the backer board. We found a suggestion online to dampen HardieBacker board before spreading the thin set. "Buttering" the backs of the tiles with thin set also forms good adhesion and is highly recommended.

Our first batch of thin set seemed too thick. BFF mixed subsequent batches thinner; the consistency of mayonnaise is about right for it to flow when you set the tiles down into it.

• Use spacers flat with large format tiles

As mentioned in the previous blog, we found that standing the spacers up was not as effective as laying them down between the tiles where the corners met. BFF layered one on top of another for strength, and they did not move around, but it does require some digging with a screwdriver to extract them -- or in my case, three cats with claws, who voluntarily helped here and there.

In the end, only one tiny triangle next to the wall failed to adhere using the large-format tile thin set. We glued it down with Loctite PL400 subfloor all-weather adhesive left over from gluing the backer board before the board was screwed down.

Give the thin set a minimum of 24 hours to set up -- 48 is better. It takes a week to fully cure, but you can walk on it and grout it after 24-48 hours.