Can I Tile My Outdoor Wooden Balcony?

The Short Answer

• Wood alone is not an acceptable substrate for tile, which means you need a concrete board or other type of acceptable underlayment. You also need to ensure that the wood subfloor is strong enough to support the tile. In addition, since you need to add layers of wood and substrate for structural support, the finish height of your new balcony floor is going to be several inches higher than it was before, which is something you have to take into account if you are transitioning from one floor to another.

Joist Spacing

• The spacing of the floor joists is important for the structural integrity of a ceramic tile installation due to the inherent deflection in floors. This is the up-and-down movement of the floor. For normal tile installations the maximum spacing for floor joists is 16 inches on center, although the preferred spacing is 12 inches on center if you are dealing with heavy natural stone tiles. Anything greater than 16 inches is not acceptable for tile installations as there is too much space between the joists for allowed deflection.

Subfloor Requirements

• The minimum thickness for a substrate beneath a tile installation is an inch and one-eighth. This is created by double sheets of five-eighths-inch thick exterior grade plywood installed on top of each other. If your balcony only has a single layer of plywood from the previous flooring material, or is a wooden balcony without a subfloor, you will need to add sufficient layers of wood to prep the area for tile.

Underlayment

• Of equal importance to the subfloor is the underlayment. Concrete and fiber boards are the most common type of underlayment used, but it is important to understand they do not add any structural elements to the installation, but rather provide an acceptable bonding surface for the thinset mortar used in tile installations. This is installed on top of the wood substrate and counts towards the overall thickness of the new floor.