With a scoop of freshly placed mixed floor tile mortar on the subfloor, the next step is to spread it deep enough to set the floor tile and then “embed” the mixture so it will properly bond with the floor. Using the flat edge of your notched trowel, gently spread the mortar to a size large enough to set the first floor tile in place.

When doing this, be very careful not to cover up your chalk line or any other important alignment guides you may have made on your floor earlier, which were necessary for dry-lay projection and line-of-sight direction. It’s not a big deal if you don’t quite get to the chalk line, as it’s better not to get to it. By the time you press the tile onto the mortar bed, this will really squeeze the mortar to cover a larger area, so it’s best to have it hang down a bit from the lines when spreading.

In this sense of initially typing the mortar, you want to not only spread it like you’re buttering toast, but more like the way a child would butter a slice of toast. To explain this, I mean not methodically spreading the mortar in just one direction, say from right to left, for example, but following a more irregular pattern by spreading it from several alternating angles. This allows the tile mortar to adhere much better to the floor by keeping the spread angles erratic, but smooth enough not to go over the marks.

Once you’re happy with the insertion process, which should take about 30-60 seconds per floor tile, you’ll also want to make sure the mortar bed is about 1/2″ to 3/4″ deep. inch deep. The next step after this is to place the ‘grooves’ into the mortar bed with the notched edge of the trowel. When done correctly, this should basically turn your mortar bed into something very similar to a freshly plowed field.

To do this correctly, always pull the paddle towards you and not push it away. Not only is it easier on your back, but it also allows you more control of your lines, so the first step is to get into a comfortable position. Next, place the notched edge of your trowel on the edge of your spread mortar, angle it at about a 45-degree angle with the flat edge facing you, press down hard on the floor, then pull back straight. always keeping the pressure down.

You should hear a steady scraping sound when done correctly, and when you reach the end of your scrape, lift the paddle up slightly, rotate it about 90 degrees, and then slide it down. This will create a small mound of excess mortar at the end of your ‘plowed field’, cleaning it up with the trowel and preparing it to use for the next floor tile to be laid on a new bed.

That’s basically all it takes to tap and spread your mortar, and once you get the hang of it, you’ll soon find that it follows a simple, rhythmic pattern. However, one last important point is to always keep the ‘grooves’ in a straight line. Never attempt wavy lines and graceful curves, as the mortar will not spread properly once the floor tile is set on top with pressure, and can cause unwanted trapped air bubbles under the floor tile when it dries. If there is no solid support below a point in a floor tile, such as an air pocket, then you could be looking at a potentially cracked tile just waiting to happen over time.