brycenesbitt
Senior Member
- Location
- United States
I'm trying to compile and read up on NM cable in unfinished basements.
Our local inspectors seem OK with NM in basements (ceiling or high up on wall) as long as it is not nailed to lower joist edges.
How about yours?
The code mentions a distinction between a dirt crawl and a unfinished (storage) basement. Is there any place the rules are different for the two types?
300.4 Protection Against Physical Damage. Where subject to physical damage, conductors, raceways, and cables shall be protected....
334.10 Uses Permitted. Type NM, Type NMC, and Type NMS cables shall be permitted to be used in the following except as prohibited in 334.12 [which does not seem to contain anything relevant]: (1) One- and two-family dwellings and their attached or detached garages, and their storage buildings. […]
Our local inspectors seem OK with NM in basements (ceiling or high up on wall) as long as it is not nailed to lower joist edges.
How about yours?
The code mentions a distinction between a dirt crawl and a unfinished (storage) basement. Is there any place the rules are different for the two types?
300.4 Protection Against Physical Damage. Where subject to physical damage, conductors, raceways, and cables shall be protected....
334.10 Uses Permitted. Type NM, Type NMC, and Type NMS cables shall be permitted to be used in the following except as prohibited in 334.12 [which does not seem to contain anything relevant]: (1) One- and two-family dwellings and their attached or detached garages, and their storage buildings. […]
334.15 Exposed work. In exposed work, except as provided in 100.11(A), cable shall be installed as specified in 334.15(A) through (C).(A) Type NM. Type NM cable shall be permitted as follows: (1) For both exposed and concealed work in normally dry locations except as prohibited in 334.10(3)....
(A) To Follow Surface. Cable shall closely follow the surface of the building finish or of running boards.
(B) Protection from Physical Damage. Cable shall be protected from physical damage where necessary by rigid metal conduit, intermediate metal conduit, electrical metallic tubing, Schedule 80 PVC conduit,...,.other approved means.....
(C) In Unfinished Basements and Crawl Spaces. Where cable is run at angles with joists in unfinished basements and crawl spaces, it shall be permissible to secure cables not smaller than two AWG or three 8 AWG conductors directly to the lower edges of the joists. Smaller cables shall be run either through bored holes in joists or on running boards. Nonmetallic-sheathed cable installed on the wall of an unfinished basement shall be permitted to be installed in a listed conduit or tubing or shall be protected in accordance with 300.4. Conduit or tubing shall be provided with a suitable insulating bushing or adapter at the point the cable enters the raceway. The sheath of the nonmetallic-sheathed cable shall extend through the conduit or tubing and into the outlet or device box not less than 6 mm (1/4 in). The cable shall be secured within 300 mm (12 in) of the point where the cable enters the conduit or tubing. Metal conduit, tubing, and metal outlet boxes shall be connected to an equipment grounding connector complying with the provisions of 250.86 and 250.148.