A ceramic tile underlayment should be installed when installing your ceramic tile countertop. The underlayment serves the purpose of leveling the countertop in order to make laying the ceramic tiles easier and level. The ceramic tile underlayment can be installed in the same manner as underlayment is installed for a ceramic tile floor.
Determine the Level of the Countertop
The trick to installing a ceramic tile underlayment is to determine how level the surface of the countertop is first. This is done by taking a level and checking the countertop. Checking the countertop with the level will let you know what areas may be lower that others, requiring you to build them up in order to place the underlayment.
Laying the Underlayment
Once you determine the level of the countertop, place a backer board on the countertop. The backer board is a type of fiberglass board similar to dry wall. The backer board is used to create a surface that you can place mortar on. The mortar will be built up to a point that makes the countertop level throughout. After the mortar dries, you can begin setting the ceramic tile on top of the underlayment in order to complete the installation of your ceramic tile countertop.