Anywhere UF cable is exposed above the soil, it must be protected with conduit. Not all types of conduit can be buried in the soil. EMT (Electrical Metallic Tubing) and flexible “Raintite” are not considered suitable for burial. Aluminum Rigid will corrode away in certain soils, such as clay, or in moist areas.
What type of conduit to use outside?
Nonmetallic Conduit. Nonmetallic conduit also comes in rigid and flexible types, with benefits and specific uses for both. Nonmetallic conduit is typically made from PVC and is a good choice for outdoor residential applications. Blue electrical nonmetal tubing (ENT) is for indoor use only.
Can you use UF cable in conduit?
The NEC does not allow you to run CABLE in conduit unless it is to sleeve the conduit for protection and the conduit can't exceed 24 inches in length. UF cable is designed to be directly buried. Either that or run conduit and single THHN conductors.