RealEstate Ke > Home improvement > How to Fix Gap Between Outdoor Fixture and Wall (4 Ideas)

How to Fix Gap Between Outdoor Fixture and Wall (4 Ideas)

Heavy-duty outdoor light fixtures are often mounted to the wall to flush with the exterior.

However, old fixtures will have a noticeable gap between the lighting unit and the wall caused by a few factors, including the wall’s expansion during warm weather.

As a result, leaks will become noticeable, damaging the fixture and your home’s electrical system.

There are a couple of solutions to the problem:

  • Invest in a back plate
  • Use the backer rod to fill up any holes
  • Pack the space with fiberglass insulation
  • Fix a mounting block

What is considered an outdoor light fixture?

Outdoor light fixtures are a type of lighting system that is installed on the exterior of a building to be used outdoors.

They may be mounted to the building’s surface or hung from their support when supported by a suitable wall, post, or other fixture.

Sometimes referred to as luminaires, they are usually enclosed, weatherproof constructions with their power supply.

Examples of outdoor light fixtures include:

  • Wall lanterns
  • Gooseneck lights
  • In-ground well lights
  • Streetlamps
  • Deck lights
  • Underwater lights

Where to position outdoor wall light

Different fixtures and lights have different needs.

Whether you’re installing a new light fixture for security or replacing an old one for aesthetics, it’s a good idea to take the time to decide where you want the light to be positioned.

Emphasizing a specific area of your home with good lighting can be a difference maker in the overall feel and ambiance of your home.

Here are some ideas to help you decide where you want your wall light set:

  • outdoor porch lights
  • landscape lights
  • outdoor string lights
  • driveway entrance lights
  • exterior garage door lights
  • pier mounted lights
  • step lights
  • outdoor ceiling fan with inbuilt light
  • backyard lights
  • flush-mounted outdoor motion sensor lights
  • outdoor ceiling lights
  • outdoor pendant lighting
  • outdoor pole lamp / solar post lights

How do you seal the gap around a light fixture?

1. Purchase backing/back plate

Where gaps are too big for caulking, get a backing plate because it will connect to the backside of your existing fixture.

Also called back plates, these mounting accessories protect the wires or configurations of lamps and other things from unintentional physical and water damage.

Raised back plates eliminate the need to create a cavity into the existing structure just to accommodate the wires and junction box.

However, flush-fitting back plate products look neat and tidy and are suited for wall recesses where the thickness of the backing plates keeps the surface smooth.

2. Fill the gaps with the backer rod

You must fill deep or very wide gaps between the outdoor light fixture and the wall to prevent bugs, water, and wind from getting inside.

If you can’t find a better solution, use a backer rod sold at hardware stores.

Backer rods are specially made for indoor/outdoor installations.

These round, gray, flexible lengths of foam allow easy control of airtight caulk application to prevent over-applying the sealant in joints and cracks.

Their properties of being virtually dust free and chemically inert in moist conditions also make them suitable for electrical work and provide a professional surface finish.

3. Stuff fiberglass insulation in

Take a strip of fiberglass insulation and stuff it in the gap.

Make sure to cut a length of it long enough to extend past the fixture and wall; this way, when you put on the screws, they will hold up against the weight.

Fiberglass insulation is also non-flammable, which further protects the fixture from fire.

A fiberglass roll can also fit inside a standard patching tape roll, effectively allowing you to seal the inside of a wall.

4. Look for a mounting block

A fixture mount is a block of adjustable support that you can use to cover permanent and temporary outdoor fixtures.

They can be made from plastic or vinyl.

The good thing about the mounting block is that you can screw it into the wall.

The size will depend on where you place it and what you want to achieve.

UL electrical mounting block is yet another good option to consider.

It has a block for your receptacle or electrical piece where the wire can fit in and be attached.

Circular and rectangular cutouts are available to accommodate your fixture. Remember to look for a product that fits your fixture’s shape and size.

How to protect outdoor light fixtures

Big investments in exterior lighting can have a great impact on the safety and value of your home.

But, if your outdoor light fixtures are not installed properly, they can be a safety hazard and an easy target for thieves.

Plus, weather damage and pests can cause your outdoor light fixtures to function poorly and aggravate the situation.

But you don’t need to lose out on the beauty and value that a new outdoor light fixture can provide.

Protect your lighting system against these enemies of light by making the proper adjustments and installing protective covers for vulnerable areas as follows:

  • install light shields
  • utilize cooler lights like LEDs since insects seeking warmth won’t be drawn to them.
  • install timers on outdoor lights
  • add motion sensors
  • use outdoor-rated fixtures and bulbs
  • safeguard against lightning strikes and excess power using surge protectors


Zebedee Nambaleo
Zebedee Nambaleo

Zebedee is the founder of RealEstate Ke. He creates content by carefully examining and analyzing the real estate market, home improvement resources, and government data. His analysis is based on the principle of supplying high-quality, relevant, and in-depth information to his audience. By evaluating the current conditions and predicting future trends, he provides his audience with invaluable insights that allow them to make better decisions.