Exposed NM, NMC and NMS cable are allowed to be run in “one- and two-family dwellings, their attached or detached garages, and their storage buildings” by the National Electrical Code (NEC 334.10 and 334.15). It must “closely follow the surface of the building finish or of running boards” per NEC 334.15(A), and “closely follow the surface” means well secured flush to the wall. But the catch is that the code also specifies at 334.12(B) that “cable shall be protected from physical damage where necessary” and lists several types of conduit that are approved for protection. 

    Unfortunately, the NEC does not define what areas are “where necessary." Many building inspectors define it was any surface mounted cable below 7’-0” above the floor, but it is subject to different interpretations. We call out unprotected NM-cable below seven feet pretty often in older homes. The photo above is a classic example of how not do it: below 7”-0” and poorly secured.

    In garages with exposed wood studs, cable is considered protected when run through bored holes between the studs, but not acceptacle when run along the front face of the studs.

• • • • • • • • • • • • • • • • • • • • • • • • • • •

Here’s links to a collection of our other blog posts about ELECTRICAL WIRING:

• Which house appliances need a dedicated electrical circuit?

• Can a short circuit cause a high electric bill?

• What is the maximum spacing requirement for securing NM-cable (nonmetallic-sheathed cable)?

• Is it alright to just put wire nuts on the end of unused or abandoned NM-cable or wiring?

• What causes copper wires to turn green or black in an electric panel?  

• What are typical aluminum service entrance wire/cable sizes for the electrical service to a house?

• Why is it unsafe to bond neutral and ground wiring at subpanels?

• Should I get a lightning rod system to protect my house?

• Why is a strain relief clamp necessary for the cord connection to some electric appliances?  

• Does a wire nut connection need to be wrapped with electrical tape?

• What is the minimum clearance of overhead electric service drop wires above a house roof?

• What are the requirements for NM-cables entering an electric panel box? 

• What is the color code for NM cable (Romex®) sheathing?

• Why are old electrical components not always "grandfathered" as acceptable by home inspectors?

• How can I find out the size of the electric service to a house?

• Can old electrical wiring go bad inside a wall? 

• What is an open electrical splice?

• What are the most common electrical defects found in a home inspection? 

• What is the life expectancy of electrical wiring in a house? 

• What is an "open junction box"? 

• How dangerous is old electrical wiring? 

• What is a ground wire? 

• I heard that aluminum wiring is bad. How do you check for aluminum wiring?  

• What is "knob and tube" wiring?  

• What is the code requirement for receptacle outlets in a closet?

   Visit our ELECTRICAL page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.