This is a continuation of my electrical roughing-in series.

In this article, you will learn how to install a triple gang electrical box (also known as a three-gang box).

NOTE. THIS IS NOT A 3-WAY. A 3-WAY IS A TYPE OF SWITCH TO CONTROL A LIGHT FROM TWO LOCATIONS. A 3-GANG BOX HOLDS 3 ELECTRICAL DEVICES (LIKE SWITCHES AND PLUGS).

The only difference between installing a single gang box, a double gang box, and a triple gang box, is that a TRIPLE GANG MUST BE SUPPORTED ON BOTH SIDES OF THE BOX!

This brace (support) should be the same width as the wall.. if it’s a 2×4 wall, use a 2×4 brace. If it’s a 2×6 wall, use a 2×6 for the other side of the box.

How to install a triple-gang electrical box.

What We Cover in this Article:

  • Installing a Triple Gang Box (and Supporting It [Bracing])
  • Recap of Installing Electrical Boxes

Installing a Triple Gang Box (and Supporting It [Bracing])

three-gang-support-example-electrical-scab
A triple gang (or more) needs support on both sides of the box.
This is so when drywall goes on, it sandwiches it for a tight install.

A triple gang box requires a support on both sides of the box.

This is a code rule!! Any electrical box that is triple gang or larger (four-gang box, etc), requires a support! (This support is also known as a brace).

This brace should be the same width of the wall so that when drywall gets installed on both sides of the wall, this support (brace) gets sandwiched, and gives a strong install for the box.

Often, the drywaller screws into this support to stabilize our triple-gang box.

Note – a brace/support is different than an electrical scab.

Step-By-Step Instructions for Installing a Triple Gang Box

Installation of a triple-gang is very similar comparing to a single-gang and double-gang box, it’s just a triple-gang (or larger) needs a brace/support:

  1. Know the height of your top of box
  2. Install your screws firmly with your drill
    • Two screws for a single-gang box
    • Four screws for double-gang box (1 in top ear, 1 in bottom ear tab, 2 in the front)
    • Six screws for a triple-gang or four-gang box (1 in top ear, 1 in bottom ear tab, 2 in the front, 2 in the support/brace!)
  3. If the box is close to another box, measure to screw hole (or use a laser).

Recap of Installing Electrical Boxes

So far, we’ve covered a lot about installing electrical boxes.

You’ve learned about:

Don’t miss all the articles of my roughing-in series for electricians.

I also suggest viewing my recommended tools for apprentice electricians.. Those were my exact tools I used while I was an apprentice, and they gave me a phenomenal experience.

Oh yes, you may also like some funny electrician jokes. 😁

As always, leave a comment if you have ANY QUESTIONS. These articles and videos are here to help you learn how to become an apprentice electrician!