What Size Nails Do You Need for Siding?
Short answer: use corrosion-resistant siding nails long enough to penetrate at least 1¼″–1½″ into the studs or sheathing — commonly 1½″–2″ for vinyl and 2″+ for Hardie board — and match the nail type to the material. The material drives the choice.
By material
| Siding | Nail length | Type & notes |
|---|---|---|
| Vinyl | ~1½″–2″ | Aluminum or galvanized roofing/siding nails; must reach ~¾″ into framing. Do not drive tight — leave ~1/32″ so the panel can move. |
| Hardie / fiber cement | ~2″+ (to the studs) | Hot-dipped galvanized or stainless. Seat flush, never overdrive (it cracks). |
| Wood / cedar | ~1½″–2½″ | Stainless or hot-dipped galvanized to avoid staining; ring-shank holds best. |
Vinyl siding: the loose-nail rule
Vinyl expands and contracts a lot with temperature, so it must hang, not be pinned. Nail in the center of the slot, and leave about 1/32 inch between the nail head and the panel so it can slide. Overdriving vinyl causes buckling and cracks. Set your gun's depth low and check on a scrap.
Hardie board: corrosion + no overdrive
Fiber cement demands corrosion-resistant nails (hot-dipped galvanized or stainless) long enough to reach the studs, seated flush. Bright or electro-galvanized nails will rust. More in our Hardie nailer guide.
Coil siding nail sizes to buy
Coil siding nailers run 15° wire-coil siding nails, generally 1¼″ to 2½″. For most exterior work, 2″ hot-dipped galvanized ring-shank coil siding nails are a safe default; step to stainless for cedar and coastal jobs.
Frequently asked questions
What size nails for vinyl siding?
About 1½″–2″, reaching ~¾″ into framing, driven loose (leave ~1/32″) so the panel can move.
What nails for Hardie board?
Hot-dipped galvanized or stainless, long enough to hit the studs (~2″+), seated flush and never overdriven.
Can I use roofing nails for siding?
Sometimes for vinyl, but siding nails are the right tool. Never reuse siding nails for shingles — see roofing vs siding nailer.