Species data
Red Alder
Alnus rubra - a hardwood from coastal western North America. Also sold as alder, western alder.
Properties at a glance
| Janka hardness | 590 lbf |
| Stiffness (MOE) | 1,380,000 psi |
| Specific gravity | 0.45 |
| Density | 28.1 lb/ft3 (450 kg/m3) |
| Weight per board foot | 2.34 lb |
| Shrinkage, green to oven-dry | 7.3% tangential / 4.4% radial |
| Movement coefficient (CT / CR) | 0.00256 / 0.00151 |
| Indicative price | $4.00 per board foot (estimated) |
Values are at about 12% moisture content. Density is specific gravity times 62.4; a board foot is one twelfth of a cubic foot, so weight per board foot is that density divided by twelve. Anything marked estimated is our own figure, not a measured one.
How Red Alder compares
Measured against the 113 solid woods in this database: it is harder than 27% of them, heavier than 19%, and stiffer than 26%.
What that means in the shop
A 4/4 board 8 inches wide and 8 feet long is 5.33 board feet, so in Red Alder it weighs about 12.5 lb. A stack of ten is 125 lb - worth knowing before you load a rack or a car.
Against red oak, the trade's usual yardstick at 1,220 lbf, Red Alder is about 48% as hard and 64% as heavy.
Its shrinkage is 7.3% tangential against 4.4% radial, a ratio of 1.7 to 1. The wider that ratio, the more unevenly a flatsawn board moves across its width as humidity changes, and the more it wants to cup; anything near or above 2 to 1 is worth quartersawing or restraining for panels and wide tops. This one moves comparatively evenly.
Woods of similar hardness
Closest to Red Alder on hardness in this database: Port Orford Cedar (590 lbf), Tamarack (590 lbf), Alaska Yellow Cedar (580 lbf), Spanish Cedar (600 lbf). Similar hardness does not mean similar behaviour - check density and movement before substituting one for another.
Working with it
Workability. Works and sands very easily; its softness means denting is a risk without care
Durability. Non-durable to perishable; mill and dry logs quickly to prevent staining
Typical uses. furniture, cabinetry, millwork, veneer, musical instruments.
Related calculators
Sources
- The Wood Database - Red Alder
- Dimensional change coefficient table (Hoadley / FPL Wood Handbook), reproduced by Popular Woodworking
MOE, SG (12% MC), Janka and shrinkage from The Wood Database (cites USDA FPL Wood Handbook). CT/CR from the FPL/Hoadley table where listed. Uses, region, durability, workability summarized from The Wood Database. Price indicative.
These calculators are for planning and estimation. Engineering results (shelf sag, wood movement) use published average material properties; real boards vary by grade, grain, moisture and defects. Verify load-bearing designs with a professional.