How to Correctly Trowel Mortar by the CTEF
One of the most commonly asked questions is about properly applying mortar. It’s even one of the most popular CTEF blogs ever published. After all, applying thin set mortar is one of the most critical pieces of installing tile properly. If thin set mortar is not applied correctly, the tile can crack or break. Nobody wants that, least of all your customer.
First, let’s start with the purpose of thin set mortar and Large & Heavy Tile (LHT) mortar. These products support the tile and bond to both the substrate and the back of the tile. When all of this is accomplished correctly, the tile installation will last for many years to come.
Follow these three steps to ensure a proper installation:
#1. Choose the Right Trowel
When choosing a trowel, you need to select the right type and notch size. You need a notch that allows enough mortar to be applied in order to support the tile.
#2. Spread Completely
As the CTEF states, “Make sure to spread the mortar completely up to the layout line. Installers who stay away from the chalk line to eliminate having mortar squeeze up in the grout joints leave dangerous voids which can result in catastrophic failure, especially in areas subject to high heels, point loads such as pallet jacks, pianos or a refrigerator.”
#3. Play it Straight
To get the best coverage on the back of the tile, trowel the mortar in one direction with a left to right movement. As the CTEF explains, “Place the tile into the mortar moving it in a back and forth motion perpendicular to the trowel ridges. This movement collapses the trowel ridges into the valleys leaving very few if any voids in the mortar which supports the entire back of the tile.
“As the NTCA video explains, trowel ridges running in straight lines are much easier to collapse. Furthermore, they assist with air removal to maximize mortar coverage and ensure a strong bond to the tile and substrate.”
As always, you can come into any of our D&B Tile locations across South Florida and our team of tile experts will help you with all of your questions.