Trenching a 20A GFCI circuit to a shed in Jacksonville, Florida.

Depth: In Jacksonville (NEC and Florida follow the 2020 IRC), a 20A GFCI circuit to a shed requires minimum 18 inches of burial depth for rigid metal conduit (RMC), intermediate metal conduit (IMC), or PVC conduit. If using direct-burial cable (UF or USE), the minimum is 24 inches. Schedule 80 PVC requires 18 inches; Schedule 40 requires 18 inches only if GFCI-protected at the breaker.

Call Before You Dig: Yes. Florida 811 (call 811 or visit floridas811.com) is mandatory before any excavation. They’ll mark underground utilities within 2 business days. Failure to call can result in fines and dangerous strikes.

Additional Notes:

• GFCI protection is required at the shed (receptacles) and/or breaker.
• Use weatherproof boxes and covers rated for wet locations.
• If trench crosses property lines, verify local easement rules.

Bottom Line: Dig 18" minimum (conduit) or 24" (direct burial), and always call 811 first.

Depth (NEC 2023 / Florida Building Code 8th Ed.):

• 24 inches for direct-burial UF-B cable (NEC 300.5 Table 300.5).
• 18 inches if in PVC conduit (Schedule 40 or 80) (NEC 300.5 Table 300.5).
• 12 inches only if in RMC/IMC metal conduit and the circuit is GFCI-protected and ≤20A (NEC 300.5 Table 300.5, Note 4). Since you are running a 20A GFCI circuit, 12 inches in RMC/IMC is legal.

Jacksonville Specifics (COJ / JEA):

• Call 811 (Sunshine 811) at least 2 full business days before digging. It is Florida law (Ch. 556, F.S.). They locate JEA electric, water, sewer, gas, and comms to the meter/transformer.
• Private locates: 811 does not locate lines past the meter (e.g., shed feed, irrigation, private gas, landscape lighting). Hire a private locator if unsure.
• Permit: Required for new circuits to outbuildings (FBC Building 105.1). Pull an electrical permit with the City of Jacksonville Building Inspection Division. You need a rough-in inspection (trench open) and final.
• Wire: Use UF-B or THWN-2 in conduit. NM-B (Romex) is prohibited underground/wet locations (NEC 334.12(B)).
• Shed Subpanel: If the shed has >1 circuit, you need a subpanel with ground rod(s), isolated neutral/ground bars, and 4-wire feed (NEC 225.31, 250.32).

Bottom line: Trench 12" in RMC/IMC (cheapest deep option) or 18" in PVC. Call 811 first. Pull a permit.