Finally, it is time to start laying tile. Your surface is prepared and you have your layout on paper. Now you need to get the layout onto the surface to be tiled. This can be done using a chalk line to snap lines indicating where the tile goes. It is not necessary to snap a line for every row but it is a good idea to mark a starting row and then mark about every fourth row in both directions. It is best to mark the lines of the edge of the tile that will be closest to you as you are tiling. To preserve the marks you can lightly go over them with a clear acrylic spray from a can.
Tile is set into either a ready to spread mastic or a thinset mortar that is mixed as you work. We prefer to work with Thinset, as it has a better bond and is more flexible to environmental conditions and size of project.
It is important to pay attention to The details of mixing thinset mortar; this will determine the strength of the bond that holds the tile to the substrate. We recommend using a polymer modified thinset. This is especially important here in the Brazos Valley where our clay soils cause foundation movement. If you are mixing large batches of thinset, it is a good idea to use a five gallon bucket and a paddle made for mixing mortar (not paint) chucked into a ½” drill.
It is important to maintain a clean bucket and paddle. Old dried or drying thinset can act as a catalyst and cause the fresh batch to setup more quickly than you want. Always use clean water to mix thinset and grout.
Add the water first and then the dry mix. Mixing it until it is the constancy that you want. It should be something like cake frosting, stiff but easily spreadable. Try not to get crazy with the paddle; you want to avoid mixing in too much air as this will compromise its bounding strength. Now it’s time to let it slake (rest) for 10 minutes. This allows any remaining clumps to absorb moisture and dissolve into the mix. Mix one more time and you are ready.
Now that your thinset is ready, and work surface is clean, you’re ready to start laying some tile. But wait, temperature is important when setting tile. Ideally it will be between 65° and 75° but here in the Brazos Valley we sometimes have to push the envelope. In both cooler and hotter temperatures you will want to spread less at a time. Also try not to work in direct sunlight as this will cause the thinset to harden too quickly. Never try to set tile when it is freezing.
You will need the right trowel for setting the size tile that you are working with. If you are setting tile that is between 4” and 8” Use a ¼”X ¼” notch. If your tile is between 8” and 16” you will need a ¼” X 3/8” Trowel and if your tile is larger than 16” you will need a ½”X ½” trowel.
Start by spreading thinset onto the work surface using the unnotched side of your trowel. Spread an even layer about the thickness of your notchs. Spread the thinset with a low angle pressing down to force the material into the pores of your work surface. Now using the notched side of the trowel you will rack groves into the thinset. Hold the trowel at about a 45° angle. Maintaining a constant angle is important. Uneven ridges will result in uneven tile. As you start out, it is a good idea to not spread too much at a time. Not only will this prevent the thinset from drying too much before you have set to it, it will also help you keep the ridges more consistent. As you reach longer distances, it is harder to maintain a consistent angle.
Remember to work your way out of a room. Tile needs at least 24 hours before being walked on. Most of the time you will want to set full tiles before beginning to work on cut tiles. As you lay tile it is a good idea to use a thin margin trowel to remove thinset from the grout lines before you set then next tile. It is far easier to do it before you lay the tile than after. You do not want the thinset to show through the grout. And, a thinner grout line that has thinset in it will crack more easily. When thinset gets on the surface of the tile have a damp cloth handy to wipe it off right away.
Next time: grouting.