Repair An Outdoor Light Fixture

Dear Mr. Electrician:  How do I repair an outdoor light fixture that is not mounted correctly on the front of my house?

Answer:  You can repair an outdoor light fixture mounting problem sometimes by using a siding box.  They are available in a few styles to accommodate various sizes of siding on the house.

NOTE: Some text links below go to applicable products on Amazon.  As an Amazon Associate, I earn from qualifying purchases.  Using my links helps to keep this website FREE.

Below are photos from a repair of an outdoor light fixture with a funky electrical box mount that I corrected for a client by using a siding box.

Side view of an outdoor luminaire mounted to an indoor electrical box that is covered with duct tape and caulk.
Side view of an outdoor luminaire mounted to an indoor electrical box that is covered with duct tape and caulk.

When I first saw the above outdoor light fixture mounted this way I had no idea what to expect.  I had to use my razor knife to cut into the white blob behind the outdoor light fixture and discovered duct tape beneath.

Side view of a lighting fixture mounted outside on vinyl siding to an indoor electrical box.
Side view of a lighting fixture mounted outside on vinyl siding to an indoor electrical box.

The outdoor light fixture was attached to the outside wall using a metal, surface-mounted, indoor, octagonal electrical box that was wrapped in duct tape and covered in caulk.  This was not a good method for attaching an outdoor light fixture to a building.

Normally a pancake electrical box would be mounted to the surface of the Oriented Strand Board (OSB) sub-surface and the outdoor light fixture would be attached to that.  The vinyl siding would be cut around the pancake box.

Though a pancake box is shallow, the National Electrical Code (NFPA 70) approves its use because the cubic inches of space inside the outdoor light fixture canopy (Indoor light fixtures also) is permitted to be included when calculating the number of wires permitted.

However, a pancake box does not always provide a good solid-level surface to support the light fixture.  This varies by the surface of the wall of course.

Top Of Page

The old fixture, duct tape, and caulk is removed to reveal an indoor electrical box with some of the knockouts removed
The old fixture, duct tape, and caulk are removed to reveal an indoor electrical box with some of the knockouts removed.

The octagonal indoor electrical box had two of its knockouts removed and was covered with duct tape and caulk.  In addition to being awkward looking, it was not an approved weatherproof arrangement, even with the caulking.

The old metal box was not grounded as required in Article 250 in the National Electrical Code (NFPA 70).

Wires for old outdoor light fixture sticking out from the vinyl siding
Wires for old outdoor light fixture sticking out from the vinyl siding

My guess is that there was a pancake box installed originally when the townhouse was built, but for some reason, it was removed.  I had to use a razor blade scraper to remove the bulk of the caulk that had adhered to the vinyl siding.

Fortunately, the type NM electrical cable was in good working condition.  I removed the two-screw metal clamp-type Romex connector and used the plastic button-type connector packaged with the new Arlington plastic siding box that I installed.

Top Of Page

A siding box is used to mount a light fixture on vinyl siding outside.
A siding box is used to mount a light fixture on the vinyl siding outside.

A siding box is an excellent method of supporting an outdoor light fixture on vinyl siding and other surfaces.  I have used them many times to repair an outdoor light fixture installation.

In addition to siding boxes, there are also siding blocks available that do not contain a built-in electrical box.  Siding blocks work with other electrical boxes to help level and trim outdoor light fixtures.


FINISHED REPAIR OF AN OUTDOOR LIGHT

The completed repair and replacement of an outdoor fixture
The completed repair and replacement of an outdoor fixture

The #8141DBL siding box keeps the light fixture level and helps to prevent it from indenting the vinyl siding.

A young man wearing a two-tone white-with-black short-sleeved tee shirt with 2-way, 3-way, and 4-way switch wiring diagrams printed on the front. CLICK THE IMAGE to see more clothes, stickers, coffee mugs and other merchandise with wiring diagrams.
A young man wearing a two-tone white-with-black short-sleeved tee shirt with 2-way, 3-way, and 4-way switch wiring diagrams printed on the front. CLICK THE IMAGE to see more clothes, stickers, coffee mugs and other merchandise with wiring diagrams.
The completed repair and replacement of the electrical box and outside lighting.
The completed repair and replacement of the electrical box and outside lighting.

The siding box used to repair an outdoor light fixture here is made by Arlington Industries.

Click here to see another example of an exterior light fixture wiring repair where I had to pull in new wiring.

My post about light switch wiring diagrams may be helpful when doing this type of work.

Click for a FREE copy of my book “Almost Everything You Need To Know To Repair a Bathroom Exhaust Fan In Your Home.”

Get your required “Emergency Disconnect, Service Disconnect” labels and stickers to satisfy the 2023 National Electrical Code requirements in article 230.85(E)(1) and (2) by going to my Redbubble Shop here.

Visit my Link Tree home page for my social media connections and other links.

Top Of Page