Whether your garage is considered a "damp location" is a bit nuanced and depends on the likelihood of moisture being present. Here's a breakdown of the factors and how they relate to the NEC (National Electrical Code)

NEC Definitions:
Damp Location

A location subject to moderate degrees of moisture, such as some basements, some barns, and some cold-storage warehouses; and partially protected locations under canopies, marquees, roofed open porches, and similar locations.

Dry Location

A location not normally subject to dampness or wetness. A location classified as dry may be temporarily subject to dampness or wetness, as in the case of a building under construction.

Wet Location

A location subject to saturation with water or other liquids, such as locations exposed to weather, wash-down areas, and locations in direct contact with the earth.

Factors to Consider for Your Garage



Climate

If you live in an area with high humidity, frequent rain, or snow, the garage is more likely to be considered a damp location.

Ventilation

Good ventilation helps to dissipate moisture. Poor ventilation increases the likelihood of dampness.

Insulation

Insulation helps regulate temperature and reduce condensation. Lack of insulation can lead to moisture buildup.

Concrete Floor

Concrete wicks moisture from the ground. If there's no vapor barrier under the concrete slab, moisture can migrate upwards, contributing to dampness.

Roll-Up Doors

Frequent opening and closing of the doors can introduce moisture, especially during rain or snow.

Activities in the Garage

If you frequently wash cars inside, or store wet items, it's more likely to be considered damp.

Applying It to Your Situation

Based on your description (1200 sq ft residential garage, concrete floor, two roll-up doors), here's a possible analysis:

Possible Damp Location

If you live in a humid climate, your garage lacks proper ventilation, and you frequently open/close the doors in inclement weather, then, yes, it could be considered a damp location. The concrete floor without a vapor barrier exacerbates this.

Possible Dry Location (but with caution)

If you live in a drier climate, the garage is well-ventilated, the concrete floor is sealed or has a vapor barrier underneath, and you don't introduce excessive moisture through activities, it might be considered a dry location.

The Bottom Line



Err on the side of caution

It's always better to use wiring methods suitable for damp locations, even if you think it might be a dry location. This ensures safety and code compliance.

Recommendations


Do NOT use standard AC cable (Armored Cable, aka BX/MC cable)

Standard AC cable is definitely not allowed in damp locations because the paper wrapping around the conductors can absorb moisture, leading to corrosion and potential electrical hazards.2.

Acceptable Alternatives for Damp Locations



Type NM-B Cable in Conduit

Enclose the NM-B cable in PVC or metal conduit. This protects it from physical damage and moisture.

Type UF-B Cable (Underground Feeder)

UF-B cable is designed for wet locations and can be used in damp locations. This is a common choice.

Individual THHN/THWN Conductors in Conduit

Run individual THHN/THWN wires inside conduit. THWN is rated for wet locations.

Liquidtight Flexible Metal Conduit (LFMC) with THWN Conductors

This is a good option for connections to motors or equipment that may vibrate or move.3.

Consult a Qualified Electrician

The best advice is to consult a licensed and qualified electrician in your area. They can assess your specific garage conditions and determine the appropriate wiring methods to meet local electrical codes and safety requirements. They can also advise on proper grounding and other electrical safety considerations.

In summary, while your garage might technically qualify as a dry location under ideal circumstances, it's safer and more prudent to treat it as a damp location and use appropriate wiring methods. Don't use standard AC cable. Using UF-B cable or THHN/THWN in conduit are good options. Always prioritize safety and consult a professional electrician. Flag for review