What do you need to put on top of a wooden porch floor before putting porcelain tile it?

Before installing porcelain tiles on a wooden porch floor, you will need to prepare the floor by installing a backer board. This is a thin, rigid material that will provide a smooth, stable surface for the tiles to be adhered to. The type of backer board you use will depend on the specific type of porcelain tile you have chosen and the condition of your porch floor. Common types of backer boards include:

1. Cement Board: Cement boards are made of a mixture of cement, sand, and fibers. They are strong, durable, and moisture-resistant, making them a good choice for outdoor applications. Cement boards can be installed directly over the wooden porch floor, provided that the floor is structurally sound and level.

2. Plywood: Plywood is a type of engineered wood that is made from thin layers of wood glued together. Plywood is a less expensive option than cement boards, but it is not as moisture-resistant. Plywood can be used as a backer board if it is treated with a waterproofing sealant before installing the tiles.

3. OSB (Oriented Strand Board): OSB is a type of engineered wood that is similar to plywood, but it is made from larger pieces of wood. OSB is a less expensive option than plywood and cement boards, but it is also less moisture-resistant. OSB can be used as a backer board if it is treated with a waterproofing sealant before installing the tiles.

Once the backer board is installed, you can then begin installing the porcelain tiles. Be sure to use a thin-set mortar that is specifically designed for outdoor applications. Follow the manufacturer's instructions for mixing the thin-set mortar and installing the tiles.