Stainless steel siding screws for cedar should be 304 grade inland and 316 near salt. Use #8 x 1-5/8" for clapboard or shiplap into sheathing, and #10 x 2" into studs or board and batten. Anything with exposed iron in it reacts with cedar tannin and streaks it black.
We've built decks for homes and for businesses for over 28 years, and fought the same cedar tannin problem on every fence and picket we've fastened. For this post we went through the Western Red Cedar Lumber Association siding guide and the threads where cheap plated nails wept black down cedar.
TL;DR
- Use Eagle Claw SS wood screws for cedar siding. Eagle Claw’s 304 and 316 stainless steel siding screws have nothing in them that reacts with cedar tannin, the flat head with countersinking nibs seats flush in 3/4" cedar without a countersink bit, and the 1,750 box brings the #8 down to $0.08 a screw.
- Grade: 304 inland, 316 within about 3 miles of salt water.
- Size: #8 x 1-5/8" for clapboard and shiplap into sheathing, #10 x 2" to 2-1/2" for board and batten or straight into studs, at least 1-1/4" in solid wood.
- Spec: star drive, Type 17 cutting point, flat head with nibs.
- Coastal: the same screw in 316 marine grade stainless steel deck screws, #10 x 2-1/2".
- Where to get them: the 304 grade stainless steel deck screws collection. Contractors get 10% off and free shipping.
| Screw | Drive | 100 pack | 1,000 pack | 1,750 box | Per screw, 1,750 box |
|---|---|---|---|---|---|
| #8 x 1-5/8" 304 | T20 | $21 | $93 | $143 | $0.08 |
| #10 x 2" 304 | T25 | $28 | $136 | $218 | $0.12 |
| #10 x 2-1/2" 316 | T25 | $38 | $203 | n/a | $0.20 at 1,000 |
Not sure yet? Try before you buy.
Drive a few of our 304 and 316 stainless steel screws into an offcut of your cedar siding before you order a full box. See how the Torx drive and countersinking nibs seat the head flush in 3/4" boards, with nothing in the screw to streak the wood.
Why Use Stainless Steel Siding Screws on Cedar Instead of Galvanized?
Use stainless steel siding screws on cedar because iron reacts with cedar tannin and weeps black streaks that never come out. Hot-dipped galvanized is approved for cedar too; the trouble is plated and coated screws, which are carbon steel under a thin skin that wears through on the way in.
One wet day with iron in the wood is all it takes, and every head has a dark drip under it for the life of the wall.
Fence builders who've watched cheap plated nails go bad in cedar put it plainly. They "weep a stain down the board." It won't fail the build, but it's ugly, so "spend the less than $1 a foot and get stainless." Another: "long drips of stain that can never be removed."
- Hot-dipped galvanized is approved by the Western Red Cedar Lumber Association, along with aluminum and stainless steel. The thick zinc layer keeps iron off the wood as long as it stays intact. Electro-galvanized is the thin version that wears through on the way in.
- Coated deck screws are carbon steel underneath. One chipped coating, one streak.
- 304 stainless steel siding screws have nothing that reacts with the wood. The chemistry is in our post on the best screws for cedar fencing.
What Size Stainless Screws for Siding, and Where to Put Them
Use #8 x 1-5/8" 304 stainless steel deck screws for 3/4" clapboard and shiplap into sheathing, and #10 x 2" to 2-1/2" for board and batten or straight into studs. The rule under all of it is 1-1/4" of screw in solid wood. Subtract the siding thickness from the screw length, and if you're short, go up a size.
| Siding type | Screw for cedar siding | Where it goes |
|---|---|---|
| 3/4" clapboard or bevel over sheathing | #8 x 1-5/8" 304 | one per stud, just above the lap of the board below |
| 3/4" shiplap or tongue and groove | #8 x 1-5/8" 304 | one per stud through the center of the face. siding up to 6" wide gets one nail 1" up from the lap. |
| Board and batten, 1x boards and battens | #10 x 2" to 2-1/2" 304 | into studs, through the batten |
| Repairs and boards that may come off again | #10 x 2" 304 | into studs |
| Any of the above within 3 miles of salt | #10 x 2-1/2" 316 | same placement |
Pre-drill within 2" of every board end so the screw doesn't split the cedar. Bit sizes are in our post on what size hole to drill for wood screws.
One fastener per bearing point, through the center
Boards up to 6" wide take one fastener per bearing point, driven through the center so the board can shrink and swell without cracking. Boards 8" and wider take two, about 3" apart. The numbers come from the Western Red Cedar Lumber Association siding pre-installation guidelines.
- Studs at 24" on center over solid sheathing, 16" on center without it.
- Never pin two boards with one fastener. On lap siding, drive the top board just above the board below it. One screw through two boards, or two through one, splits the board across the middle.
- Center fastening is the fix for movement. A builder putting up hemlock siding went with stainless steel deck screws at the center of each board, one per contact point, so it could move without cracking.
304 or 316 Stainless Steel Siding Screws?
304 stainless steel siding screws inland, 316 if your home is going to be buffeted by salty spray or splashing waves. Either works on a lake house. Around a chlorine pool, go 316. Neither streaks cedar, and neither tea stains. 316 has molybdenum in it, so it holds up to salt spray where 304 can start to pit after years by the ocean. The full breakdown is in our post on 304 vs 316 stainless steel.
Trim Head or Flat Head Screws for Siding?
Flat-head stainless steel siding screws with countersinking nibs seat clean and hold better on thick boards; trim heads disappear but pull down less. We carry flat heads only, so here's the honest call.
- Flat head with nibs: board and batten, thick boards and anything fighting cupping. Most pull-down, no countersink bit.
- Trim head: when the head has to vanish in a stained face or the tongue of shiplap. Starborn's Deckfast 305 stainless steel trim head, #7 x 2-1/4", is about $0.20 a screw. Simpson's 410 stainless steel trim head, same size, is about $0.25, but 410 surface-rusts far sooner than 304 or 316. Take the 305.
- Never: drywall screws. A homeowner asked if the contractor should redo a cedar wall, and the first reply nailed it: "definitely drywall screws, what a clown show."
What Stainless Steel Siding Screws Should You Buy?
The stainless steel siding screws you should buy for cedar are Eagle Claw stainless steel fasteners, 304 inland and 316 near salt. Plated screws drip black after one wet week. We nail long lap runs with Simpson Strong-Tie ring-shank nails. Try a sample pack first, or shop the full range.
Cedar Siding Nails or Screws: What Carpenters Use
Carpenters nail most cedar siding and screw the parts that need holding power or might come off again. Nails are faster from a gun and cheaper. Screws hold flat against cupping and back out clean.
- Nails for: clapboard, bevel, shiplap and tongue-and-groove runs. Stainless steel ring-shank siding nails like Simpson's 2-1/2" 13-gauge 304, about $0.06 a nail.
- Screws for: board and batten, shingles, repairs, and any board you may want to pull later.
- The honest split: a finish carpenter who blind-nailed cedar over 1x4 strapping shot two 15-gauge stainless steel finish nails per strap and says you can't see them from a short distance.
The copper collation wire trap
Check what your stainless coil nails are collated with before the first one goes into cedar. A crew trimming a log house found out too late that theirs were collated with copper wire, and the cedar stained anyway. Plastic or stainless steel collation only.
Things to Keep in Mind
- Over-driving splits thin cedar. Set the clutch so the head seats flush and stops.
- Streaks are permanent once they start. Nothing washes or sands iron tannate out of cedar.
- Vinyl siding takes a different screw. A wood screw driven tight buckles vinyl.
