Proper routing of electric wires in metal studs (C) Carson Dunlop AssociatesElectrical Wire Clearances
Wiring an electrical receptacle: distances from pipes, ducts, wiring nail & damage protection
     


InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

Electrical wire clearance distances, spacings, when wiring up a wall receptacle (plug or "outlet"), switch or similar device.

Here we explain how far electrical wiring should be kept from hot HVAC ducts, pipes, the surface of wall studs or ceiling joists, and similar restrictions. This article series describes how to choose, locate, and wire an electrical receptacle in a home.

Electrical receptacles (also called electrical outlets or "plugs" or "sockets") are simple devices that are easy to install, but there are details to get right if you want to be safe. Page top illustration courtesy Carson Dunlop Associates.

Green links show where you are. © Copyright 2015 InspectApedia.com, All Rights Reserved.

Electrical Wire Clearances from Ducts & Pipes

We also don't route wires too close to places where the wires can be damaged by heat from a heating appliance or chimney, flooded, etc. as you'll see depicted in the two Carson Dunlop sketches below.

Proper routing of electric wires in metal studs (C) Carson Dunlop Associates Proper routing and support of electrical wire (C) Carson Dunlop Associates

Also you'll note in the two Carson Dunlop sketches just below that wires need to be routed through the center of wall studs, ceiling or floor joists, or if there is less than 1 1/4-inches of clear space between the wire opening in the stud or joist and the joist face you must use a nail plate or NAIL STOPS(shown below) to protect the wire from penetration from a nail or screw that someone may drive into the stud or joist later.

Proper routing and support of electrical wire (C) Carson Dunlop Associates Proper routing of electric wires in metal studs (C) Carson Dunlop Associates


Nail Stop Simpson Strong Tie NS2 16Ga (C) D Friedman

 

Wires running in walls anywhere from floor level to seven feet above the floor (U.S.) or five feet above the floor (Canada) must be protected from nails driven through walls.

Our photo (left) illustrates a 6-inch NS-2 Nail Stop produced by Simpson Strong-Tie. Simpson Strong-Tie catalogs these nail stops as Protecting Shield Plate Nail Stoppers.

Details about using these steel plates to protect electrical wire (and also pipes) in buildings are at NAIL STOPS to PROTECT WIRES or select a topic from the More Reading links shown below.

Reader Question: what is the minimum height that indoor house wiring must be above the ground or floor level?

When running wire for a basement, is there a min height the wires must be off the ground? Not the outlet box, but the wire running through the joists. Justin Sheppard

Reply:

No, Justin. But if there is the slightest danger that wires will be nicked by someone driving a nail into a stud though which the wires are run be sure to use steel plates to protect the wire where it passes through the studs. Simple nail plates are available at any building supplier.

Reader Question: armor required around electrical wire run through concrete?

I am running a new 15A outlet into the back of a bookcase in a 50 year old house with updated electrical. The wire runs out the back of the retrofit box and down through the concrete foundation into the crawlspace to a wire I plan to splice into. Do I need to put armor around the wire run through the foundation? It goes through open air for about 2 feet and there is no way to secure it to anything.

Thanks!
Tom - 7/19/12

Reply:

You need to look at the type and rating of the electrical wire to determine if it is permitted to bury it in concrete or not.

Reader Question: how do I increase the projection of outlets into a room so I can add a kitchen backsplash

Gang Box Extender Electrical Box Extension from Arlington IndustriesI am unable to find instructions on how to increase the projection into the room of existing electrical outlets so that I can tile the kitchen backsplash and have the outlets be at the appropriate depth for use and safety. Do I move forward the box to which the outlet is screwed and if so how? - Anne 3/22/12

Reply: use electrical box extenders - shop for an "electrical box extension" of the proper thickness

Anne,

Building suppliers like Home Depot and also your electrical supply house sell "box extenders" in varying thicknesses, made of plastic, code approved, for the purpose you describe. The electrical box extender is sized and shaped to match the electrical receptacle box to which it is to fit. By removing the electrical receptacle from its mount on the existing box, the box extender is fit as a sort of large rectangular plastic washer, mounting between the existing box edge or surface and the mounting ears of the receptacle or switch.

Electrical box extensions are sold in plastic and steel and in thicknesses from about 1/8" up to an inch or even more. The plastic electrical "gang box extension" shown at above left is produced by Arlington Industries but there are several manufacturers. Just choose an electrical box extender that brings your receptacles far enough forward to suit the thickness of the kitchen backsplash or tile.

Watch out: don't try a makeshift substitute using washers or junk - that's an improper and unsafe repair, leaving a gap around the electrical box sides.

Reader Comments:

Anne,
I'm in the midst of a remodel that posed the same 'problem'. Work box extender rings are available at Home Depot and Lowes in the electrical department. They are plastic, color-coded frames that fit between the front edge of the box and the outlet/switch. The screws that secure the outlet/switch to the box also secure the frame in place. The frames are available in multiple thicknesses. I suggest you take a tile sample with you so that you can get the correct thickness for your project. Depending on the thickness of the tile, you may need to combine two frames of different thicknesses.

While I was changing a failed plug I noticed that the box was too deep. I looked into extenders, and plastic ones (Arlington BE1) are less expensive. Are CSA approved plastic box extenders code compliant for homes? - Gary 7/19/12

 

Continue reading at CONNECTION DETAILS or select a topic from the More Reading links shown below.

Suggested citation for this web page

CLEARANCES of WIRES at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

More Reading

Green link shows where you are in this article series.

INDEX to RELATED ARTICLES: ARTICLE INDEX to ELECTRICAL INSPECTION & TESTING

OR use the Search Box found below at Ask a Question or Search InspectApedia

...




Frequently Asked Questions (FAQs)

Click to Show or Hide FAQs

Ask a Question or Search InspectApedia

Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.

Search the InspectApedia website

HTML Comment Box is loading comments...

Technical Reviewers & References

Publisher's Google+ Page by Daniel Friedman

Click to Show or Hide Citations & References