How to Mount a Light On Top of a Mirror Bathroom Vanity

Customized spaces, even bathroom spaces, always look and feel more expensive than generic, builder-grade ones. One way to customize your bathroom, no matter the style or size, is to install an oversized vanity mirror and mount a bathroom lighting fixture on top of the mirror face itself. Bathroom lights over mirrors always add that wow factor and can elevate the overall style of the bathroom.

Brass lighting for mirror in bathroom
How to Light on Mirror

Why Hang Bathroom Lights Over the Mirror?

This strategy allows you to maximize your vanity mirror size and height (which serves to expand the space) and double up on your lighting – a win-win. This tutorial will walk you through how to accomplish this successfully, without damaging your custom-cut mirror.

Add lighting fixture on mirror
Purchase a lighting fixture

Step One: Get new light fixture

Purchase a lighting fixture that you love, because you’ll be seeing twice as much of it reflected in the mirror after installation. We recommend reading through this entire tutorial before beginning, so you have an idea of what you’ll need, when you’ll need it.

electrical wiring project

Step Two: Remove old fixture

As with any electrical wiring project, begin by flipping the breaker to ensure that there’s no power to the wires. Remove the old light fixture (if applicable), and cap off your loose wires in the electrical box. (Note: The painted-out space in this photo will soon be covered with a custom-cut above-vanity mirror.)

wires and box will hang out here

Step Three: Secure the location of the wire box

These wires and box will hang out here until you’ve installed your custom mirror, with a cutout directly over the electrical box. In many instances, a lighting fixture electrical box will be round; in this case, it’s a rectangle. Either way is fine as long as the mounting screw holes are visible and fully accessible.

Depending on your lighting fixture

Depending on your lighting fixture, the chances are high that you’ll need to purchase supplemental machine screws in a longer length than what came with your light. This is because, since you are mounting onto a mirror, you will need an additional screw length of 1/2″ or so to mount the light. This lighting fixture came with 1-1/2” screws, so we purchased 2” screws (#8 size), which worked out perfectly.

standard-sized lighting fixture mounting circle

Step Four: Prep the mounting hardware

The first thing we discovered, although there was nothing we could do to change it, was the standard-sized lighting fixture mounting circle was about 1/16” too big for our mirror cutout. This was a surprise, because the cutout was sized to fit all standard-sized lighting installation components.

Original mounting strip

As many DIYers are wont to do, we were forced to move onto Plan B: Reuse the original mounting strip, which did fit through the hole and onto the electrical box screws. There was a tradeoff with this decision, which I’ll show you all later. But it was one we had to take. Hopefully, your own mirror-cutting experience will be perfect.

Tip: Take your mounting pieces into the glass-cutters when you place your order and/or pick up your mirror to ensure that the mounts will fit BEFORE the mirror is installed.

Screw two mounting screws

Screw two mounting screws (the longer ones you purchased) into the holes on your mounting strip. You might not need to screw them in all the way. Add nuts to keep them from unscrewing when it comes time to attach the flange.

determine just how far you should screw

To determine just how far you should screw in your mounting screws, measure the depth of your light fixture’s flange. We’ll call this distance “X.”

Now measure distance X away

Now measure distance X away from the face of your mirror while holding the mounting strip next to your electrical box. The screw should extend about 1/4″ past the distance X mark on your measuring tape.

satisfied with your mounting screw lengths

Step Five: Secure the mounting plate

When you’re satisfied with your mounting screw lengths, tighten up any nuts on the back of your light fixture. Note: You can adjust your mounting screw lengths later if necessary. While it’s much easier to get it correct at this stage of the installation, this is by no means a do-or-die positioning.

strip onto your electrical box screws

Place the mounting strip onto your electrical box screws so that the mounting screws face outward.

Attach and tighten the mounting strip

Attach and tighten the mounting strip onto the electrical box with a screwdriver. Ensure that the screws are tight; these screws are largely what will bear the brunt of the mirror-mounted light fixture’s weight when all is said and done.

Hold up your light fixture

Step Six: Double check

Hold up your light fixture with the flange next to one of your now-positioned mounting screws. Verify the spacing of your screw depth, keeping in mind the depth of your light nut holes for screwing on later. Make any adjustments to your mounting screws that are necessary.

With your mounting screws positioned

Step Seven: Work the wires

With your mounting screws positioned, it’s now time to wire up your light. Have a helper hold the light fixture up for you (so it doesn’t slam against or scrape your mirror) while you connect and attach wires. Thread the fixture’s wires through the mounting strip’s center circle.

wire on the ends of your fixture wires

Expose about 1/2” of wire on the ends of your fixture wires. Twist the black-cased wire ends with the black- (or dark-)cased electrical wire end.

two black light fixture wires

With the two black light fixture wires and the one black (dark) house/electrical wire twisted tightly together, it’s time to cap them off with a wire nut.

number of black and white wires

Note: The number of black and white wires that your light fixture has depends largely on the number of light bulb positions it has; because electricity is required at two separate positions on this particular lighting fixture, two separate black wires and two separate white wires on the fixture itself are involved.

How to Light on Mirror - repeat the attach

Repeat these steps for attaching the white wires from the fixture to the white wire from the house’s electrical.

When you are installing a lighting fixture

When you are installing a lighting fixture, there should be an exposed wire in your fixture and an exposed wire from your house’s electrical. These exposed wires are called ground wires, and they are meant to attach to the earth so as to neutralize electric currents as needed. Bend the light fixture’s ground wire under the green ground screw, and tighten the green screw.

Twist and then cap both ground wires

Twist and then cap both ground wires – the one from your light fixture and the other from the house’s electrical – together.

capped connection of all wires

At this point, you should have a secure, capped connection of all wires to their appropriate counterpoints. Your helper should be starting to moan about not being able to hold up the light any longer. If both things are happening, you’re right on plan.

electrical is to wrap

Step Eight: Wrap ends with tape

The last thing you need to do with the electrical is to wrap the open ends of each wire nut and wire casing with electrical tape. This is to provide a layer of insulation and protection to any part of the wire that might, for whatever reason, be exposed outside the wire nut.

black and white wires are taped

When the black and white wires are taped, push them gently into the electrical box.

how to mount your light.

Step Nine: Attach fixture

It’s now time to mount your light. This is a critical step to do correctly. Set the flange gently onto the mirror surface with the mounting screws coming out the screw holes. The light nuts, which will go onto the ends of the mounting screws to hold the light in place, need to be screwed on. They need to be tight enough to hold the light fixture in place but not so tight that the fixture puts stress onto the mirror.

How to Light on Mirror- overtighten

Do NOT overtighten. I can’t stress this enough. A light nut that is too tight can fracture a mirror even a year later after installation. This is why you worked so hard on completely securing your mounting strip to the electrical box – the mounting strip is secure and is going to be the workhorse for your lighting fixture’s weight. All you’re trying to do at this point is keep the mirror flush against, or just touching, the mirror face. Nothing more.

Brass bathroom miror light

Step Ten: Finish 

With the flange carefully secured against the mirror face, it’s now time to make any finishing touches to your light fixture itself. Attach any lamp shades necessary, depending on the style of your lamp.

twice your lighting fixture

As was mentioned earlier, you’re probably noticing it much more at this point. You’ll see twice your lighting fixture from here on out. Hope you love it!

Install the lighting bulbs

Install the light bulbs. Flip your breaker, and test it out. Moment of truth…

Installed lighting fixtures for bathroom

It works! And it’s absolutely beautiful.

reflective power of a mirror

Talk about utilizing the reflective power of a mirror in a small space to amp up the light! This makes the small bathroom feel so much bigger and brighter.

mounting strip instead of the mounting circle

Remember how I mentioned a tradeoff when we had to use the mounting strip instead of the mounting circle? The tradeoff was that the light nuts could not be aligned parallel with the light, because of how the screw holes fell in the mounting strip. They are tilted, as you can see here.

Despite that small annoyance

Despite that small annoyance, however, the light fixture is a perfect addition to this bathroom makeover. The glass shades are subtle, while the whole fixture is both vintage-feeling but in a clean, contemporary way.

Edison light bulbs for bathroom

And, with LED Edison bulbs, the fixture really combines old and new – the best of both worlds.

Mounting a light fixture

Mounting a light fixture on top of a bathroom vanity mirror is a beautiful way to add light, height, and presence into your bathroom. We hope you’d agree.

Note: The author is an experienced, although not professional, DIYer. Neither the author nor Homedit is responsible for any injury or damage that may be a result of following this tutorial.