What does 'hot dipped galvanized' actually mean?

Hot dipped galvanized (HDG) nails are dunked into molten zinc, leaving a thick, uneven coating that lasts decades. They corrode much slower than electro-galvanized nails, which only get a thin electroplated zinc layer.

Are hot dipped galvanized nails required by code?

Most building codes require galvanized roofing nails meeting ASTM F1667 with a minimum zinc coating. HDG nails (G90 or higher) meet this easily; electro-galvanized often does not for outdoor exposure.

Hot dipped galvanized vs stainless — which is better?

Stainless lasts longer, especially near saltwater, but it costs 2–3x more. HDG is the standard for inland asphalt-shingle roofs. Use stainless within a few miles of the ocean or under copper flashing.

Hot Dipped Galvanized Roofing Nails: When to Use Them

Not all 'galvanized' roofing nails are equal. The hot-dipped variety lasts decades; the cheap electroplated stuff can start rusting in a couple of seasons. Here's when hot dipped galvanized roofing nails are the right call, and when you should pay up for stainless instead.

Hot dipped vs electro-galvanized vs stainless

The "galvanized" label on a box of roofing nails can mean two very different things. Electro-galvanized nails get a thin, even layer of zinc — pretty, cheap, and fine indoors. Hot dipped nails are submerged in molten zinc, building up a much thicker, lumpier coating that handles 20–30 years of weather without flinching.

Stainless steel sits above both. It doesn't rely on a sacrificial coating; the corrosion resistance is in the metal itself. Cost is the catch — stainless coil nails run two to three times the price of hot dipped.

What code actually requires

Most jurisdictions reference ASTM F1667 for roofing nails. The spec calls for a minimum zinc coating thickness, and hot dipped galvanized roofing nails (typically G90 or higher) clear it without trouble. Electroplated nails frequently don't, which is why they aren't allowed for exterior structural applications in most regions.

Shingle manufacturer warranties also specify HDG as the minimum acceptable nail. If you use cheap nails and the shingles fail, the warranty walks.

When hot dipped is the right call

Standard inland asphalt-shingle roofing — HDG is the default and what 95% of pros use
Pressure-treated decks — the chemistry attacks aluminum and bare steel; HDG holds up
Underlayment cap nails on synthetic or felt
Ridge cap and hip nails on standard composition shingles

When to upgrade to stainless

Within ~3 miles of saltwater coastline
Cedar shake or shingle roofs (the tannins corrode galvanized over time)
Anywhere copper flashing meets the nail (galvanic corrosion will eat HDG fast)
Tile and slate roofs where the nail will outlast multiple shingle replacements

Sizes you'll actually use

For coil roofing nailers, hot dipped galvanized nails come in 7/8", 1", 1-1/4", 1-1/2", and 1-3/4" lengths. The 1-1/4" size is the workhorse for new construction over 5/8" sheathing. Step up to 1-1/2" or 1-3/4" for re-roofs over an existing layer or for thick laminated shingles.

Browse stocked sizes on the coil roofing nails page, or check the sizing guide if you're not sure which length matches your deck thickness.