On 2009-09-10, stryped wrote:

Can type NM cable be used in a detached garage with no interior
walls?

Starting with the 2002 NEC, this was disallowed. Section 334.10 of
the 2008 NEC reads:

334.10 Uses Permitted. Type NM, Type NMC, and Type NMS cables shall be
permitted to be used in the following:

(1) One- and two-family dwellings.

(2) Multifamily dwellings permitted to be of Types III, IV, and V
construction except as prohibited in 334.12.

(3) Other structures permitted to be of Types III, IV, and V
construction except as prohibited in 334.12. Cables shall be concealed
within walls, floors, or ceilings that provide a thermal barrier of
material that has at least a 15-minute finish rating as identified in
listings of firerated assemblies.

(4) Cable trays in structures permitted to be Types III, IV, or V
where the cables are identified for the use.

Section 334.12(A) prohibits other uses. Since a detached garage is
not a dwelling unit, usage in the garage is governed by 334.10(3),
which require the NM to be concealed.

Cheers, Wayne