Sample data from Engineering Database — 375 reference tables, deterministic calculators, and Engineering AI. Sign up free
Nec Underground Cover: under 4in exterior concrete slab
NEC (NFPA 70) Table 300.5 — minimum burial cover depths for underground wiring installations by location type and wiring method (direct burial cable, rigid metal conduit/IMC, nonmetallic raceway, residential GFCI branch circuit, irrigation at 30 V or less)
| location id | col1 direct burial mm (mm) | col2 rmc imc mm (mm) | col3 nonmetallic raceway mm (mm) | col4 residential gfci mm (mm) | col5 irrigation 30v mm (mm) | location description | nec section | standard |
|---|---|---|---|---|---|---|---|---|
| under 4in exterior concrete slab | 450 | 100 | 100 | 150 | 150 | Under minimum 102 mm (4 in.) thick concrete exterior slab, no vehicular traffic, slab extends 152 mm beyond installation | 300.5 | NEC (NFPA 70) 2017 Table 300.5 |
What else is in Engineering Database
Iron Engine ↗Engineering AI at ironengine.ai
AI built for engineering. Searches the engineering database, performs calculations, gives source-backed engineering insights.
Get started for free ↗Reference Data375 engineering tablesMaterial properties, pipe and shape dimensions, code tables, and electrical ratings across mechanical, civil, chemical, electrical, materials, and manufacturing engineering.
Browse dataCalculatorsDeterministic engineering calculatorsSizing, checking, and conversion tools that run against the reference tables. Inputs are code-compliant, outputs are traceable to the source standard.
Browse calculators