More in Floors
Apply the mortar to an area of the floor, along your chalk guideline. Make sure you leave the chalk line exposed so you can use it as a guide. Use the flat side of the trowel to spread the thinset mortar on the floor (Image 1), then turn the trowel around and double back over the thinset with the notched side of the trowel (Image 2).
Don’t apply too much mortar to the floor at one time, as it will begin to set up within 20 minutes. Just work a small area at a time, spreading the mortar out and installing a few tiles before moving to the next area (Image 3). If you do have to stop for any reason after you’ve already spread the thinset down, scrape it back up and put it in the bucket. It is much easier to get off the floor while it’s wet than once it’s cured.
TOOL TIP: Typically for floor installations, a 1/4” square-notched trowel is the right tool for the job, but if your floor is rolling, uneven, or if you are working with very large tiles, it helps to use a trowel with larger notches. Recommended sizes are 3/8” and 1/2”, which are easy to find in most hardware stores.
Begin with your cut tiles in the corner of the room, following your chalk guildelines. You want to always work towards the perimeter of the room, so you can hide cuts against the wall where they’ll be less noticeable. You can use grout spacers or simply eyeball the grout lines to achieve your desired spacing.
Always work your way towards an exit, so that you can effectively tile yourself out of the room. The tile cannot be walked on for 24 hours, so it’s important that you don’t tile yourself into a corner.
TIP: It’s very important to take time to make sure the edges of your tile are level with each other. A raised corner is an unwelcome obstacle on a floor that should be flat and smooth. Take care during your install that the corners of your tile are not at different elevations from the corners of neighboring tiles. Apply more thinset to the back of tiles (or remove some) as necessary to achieve a flat, level floor.
Once the room is tiled, it needs at least a day to properly set up and cure before it can be walked upon. If you have children or even large pets, you may want to barricade the entrances of the room until the tile has properly dried.
Once the tiles are properly dried, the final step is to grout in between the tiles. Sanded grout is more durable and should be used if possible. However, very fine grout lines (1/16th of an inch or less) will require unsanded grout. Mix the grout the same way that you mixed the mortar in Step 4. Use a grout float to spread the grout evenly into the seams. Be sure coverage is thorough so there are no gaps or sunken areas. Within 10 to 15 minutes, lightly sponge off the excess and wipe down the tiles to clean them. Make sure you get any chunks of grout off the face of the tiles before it dries, as it’s much harder to remove then. Allow the grout to cure 12 to 24 hours before any intense cleaning.
After the grout has dried, it’s common to have a cloudy residue from the grout on the surface of the tiles. The best way to clean this grout film is to wipe the floors down with white vinegar, though warm water works quite well too. Do not use soap or other cleaning products.
Porcelain tile does not need to be sealed, as it’s already moisture resistant. Since the floor is not a high-moisture area like the inside of a shower, you do not need to use a grout sealer, but you may do so if you like.