What electrical cable do you use outside?

I know that gray, UF-B outdoor 14/2 electrical cable can be used both outdoors and indoors for permanent installations in Michigan. Why isn't the outdoor cable ALWAYS used for ALL 15amp indoor wiring then?

The outdoor cable can do so many more things than the indoor.

Outdoor cable:

• Is 25%-50% cheaper.
• Is highly resistant to acids, alkalis, corrosives, chemicals, lubricants, fungus, water, UV
• Can be directly buried underground for sheds, garages, barns, etc.

Both in/out door 100' reels are copper. 100' of the indoor weighs 6.1#. The outdoor weighs 6.5#.

I don't see the downside. Just the drastic lower price is enough to use it everywhere indoors and out. What am I missing? Why would the far better/safer/durable cable be so much cheaper... and NOT used everywhere 14/2 15amp is needed?

Update: 3 different DIY store employees didn't have an answer. But they found their manager that "knows all about wiring". He said you CAN use the outdoor wiring, indoors... but the building inspector would immediately raise a red flag due to the gray coloring... and give you a headache about it.

(I would think the inspector would only say "wow, you guys used the far better product than needed. Excellent job.")

Cables for external use have been designed to survive the adverse conditions in the outdoor environment. The outer layers of the cable must serve to protect the cable from external influences such as mechanical damage, water, extremes of temperatures, rodent or insect attack, UV exposure from sunlight, and ozone in the atmosphere.

There are a wide range of cables suitable for outdoor use provided they are protected from direct sunlight or other external influences. Protection can come from placing the cables in metal conduit, plastic ducting, or where directly buried, through steel wire armouring.

Unprotected outdoor cables must, as a minimum, be weather resistant, which includes protection against the typical ambient temperature range, UV light, ozone and water. There are several different methods and material types used for outdoor cables. Materials such as Ethylene propylene rubber (EPR), Polychloroprene (PCP) and Fluorocarbon naturally have a very good weathering resistance, whilst others such as PVC and Polyethylene can be made resistant with the addition of specific additives or stabilisers such as carbon black.

Return to FAQs