How Many Feet Can You Support 2 Inch EMT on a Vertical Run?

A user asked the app about strap spacing for 2 inch EMT running vertically. The rule does not change with trade size or direction: EMT gets secured at intervals not exceeding 10 feet, vertical or horizontal, plus a fastener near every termination. The trade size questions people remember from rigid conduit tables do not apply to EMT.

What 358.30 requires

NEC 2023 358.30(A) requires EMT to be securely fastened in place at least every 10 feet and, in addition, within 3 feet of each outlet box, junction box, device box, cabinet, conduit body, or other termination. So a 40 foot vertical riser between a panel and a ceiling box needs a strap within 3 feet of each end and enough intermediate straps that no interval exceeds 10 feet. Unlike rigid metal conduit, where Table 344.30(B)(2) rewards larger trade sizes with longer spacing on riser installations, EMT keeps the flat 10 foot number at every size from half inch to 4 inch.

The exceptions that help in real buildings

Two relaxations matter. First, 358.30(A) has an exception for finished bays and concealed work: where structural members do not readily permit fastening within 3 feet, the fastener can sit up to 5 feet from the termination, and an unbroken run through framing counts as supported when secured per the section. Second, 358.30(B) allows unbroken lengths of EMT to be fished through concealed spaces in finished buildings without securing, recognizing you cannot strap what you cannot reach. In open riser shafts, plan on a strut clamp or one hole strap at each floor line, since floor to floor heights near 10 feet make each slab penetration a natural support point.

Vertical runs bring a second rule

Support of the raceway is separate from support of the conductors inside it. Long vertical risers trigger 300.19, which requires conductor supports at intervals from Table 300.19(A) based on wire size; for conductors 8 AWG and smaller the interval is 100 feet, so ordinary branch circuit risers never see it, but feeders in tall buildings do. Also keep couplings and connectors made up tight per 358.42, because a vertical run hangs its weight on every fitting, and a loose set screw coupling at the top of a riser is both a support failure and a ground path failure at once.

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