Light Fixture Mounting Block

Mounting Block

• A mounting block is a flat form used to install objects that protrude from an uneven surface. It provides a flat, level surface for you to attach a light fixture’s mounting plate. You nail or screw the mounting block into place on top of the uneven surface, drilling a hole in it if necessary to pull through electrical wires or connections. Because interior walls are usually smooth, mounting blocks aren’t usually needed to install interior light fixtures. They are more commonly used for porch and other outside lights.

Advantages

• Vinyl siding is not only uneven, but each slat is set at an angle rather than being perpendicular to the house. Most slats are too narrow for a light fixture’s mounting plate; even if it did fit, the fixture would protrude away from the siding at an angle. Installing a mounting block is easier than trying to cut through the siding to mount the light fixture directly onto the exterior wall beneath. A mounting block offers protection from rain and dirt to both the exterior wall and the electrical connections behind it.

Requirements

• Don’t screw a mounting block tightly to the uneven surface, especially if it is vinyl siding. Siding tends to expand in heat and contract in colder weather. Even wood siding can be affected by temperature or moisture. Leave a ¼-inch gap between the end of the siding and the mounting block’s trimmed edges so the siding isn’t damaged when it expands. Overtime, the damage can lead to lose siding and water leakage in the exterior walls.

Considerations

• If you are installing new vinyl siding on your home, you can often get mounting blocks from the manufacturer. The vinyl mounting block will match your siding exactly and help it blend in to the exterior of your home. If you are installing light fixtures to old siding or other surfaces, paint the mounting block to match either mounting plate for your light fixture or the general exterior of your home.