Red Alder
Alnus rubra · hardwood · Western North America · moderate movement
- Janka hardness 590 lbfred oak ≈ 1,290 lbf
- Density ≈ 29 lb/ft³specific gravity 0.41 at 12% MC
- Shrinkage — tangential 7.3%flatsawn width, green → ovendry
- Shrinkage — radial 4.4%quartersawn width
- T/R ratio 1.7 : 1higher = more cupping in flatsawn stock
Shop notes The Pacific Northwest cabinet staple — mild, even texture that machines and sands cleanly, takes stain evenly, and moves modestly once dry.
Seasonal movement at a glance
Width change for red alder across a typical indoor year — 6% moisture content in the heated winter to 12% in a humid summer:
| Board width | Flatsawn | Quartersawn |
|---|---|---|
| 6″ | 3/32″ (0.094″) | 1/16″ (0.057″) |
| 12″ | 3/16″ (0.188″) | 1/8″ (0.113″) |
| 24″ | 3/8″ (0.375″) | 7/32″ (0.226″) |
| 36″ | 9/16″ (0.563″) | 11/32″ (0.339″) |
Run your own numbers
Different width, different climate swing — the calculator below is preset to red alder:
Typical swings:
Red Alder questions
How much does red alder move with the seasons?
A 12″-wide flatsawn red alder board moves about 3/16″ across a typical indoor swing from 6% to 12% moisture content; quartersawn, about 1/8″. Its tangential shrinkage is 7.3% and radial 4.4% (green to ovendry) — a moderate-movement wood.
How hard is red alder?
Red Alder rates about 590 lbf on the Janka scale — soft enough to dent in daily use (red oak is roughly 1,290 lbf). Density runs about 29 lb/ft³ at indoor moisture levels.
Is red alder good for wide panels and tabletops?
Yes, with normal precautions: its 1.7:1 tangential-to-radial ratio is moderate. Still fasten solid tops so they can move across their width.
Similar species
Spanish Cedar · Sassafras · Northern Catalpa · American Chestnut · Yellow-Poplar (Tulipwood) · Butternut
Shrinkage, specific gravity, and hardness from the Wood Handbook, FPL-GTR-282 (2021 edition), USDA Forest Products Laboratory (public domain). Values are species averages — individual boards vary with growth conditions and how they were dried.