Pacific Madrone wood movement calculator
- Janka
- —
- Density
- —
- T/R ratio
- 2.2
- Spec. gravity
- —
Pacific Madrone is a North American hardwood. The Wood Handbook strength tables list no matched specific gravity or hardness for it, so those fields are shown as “—”. It shrinks 12.4% tangentially and 5.6% radially from green to oven-dry (T/R ratio 2.2), so a 12-inch flatsawn board moves about 0.3 in (≈ 5/16 in) across a 6-point moisture swing (about 6%→12% MC).
Compute Pacific Madrone: movement, weight & board footage
Every number below is worked from Pacific Madrone's own shrinkage and density figures, not looked up from a table — change the width, moisture swing, or board size in the calculators linked alongside.
Cross-grain movement by board width
| Board width | Flatsawn (tangential) | Quartersawn (radial) |
|---|---|---|
| 2″ | 0.05″ (≈ 1/16 in) | 0.022″ (≈ 1/32 in) |
| 3″ | 0.074″ (≈ 1/16 in) | 0.034″ (≈ 1/32 in) |
| 4″ | 0.099″ (≈ 3/32 in) | 0.045″ (≈ 1/32 in) |
| 6″ | 0.149″ (≈ 5/32 in) | 0.067″ (≈ 1/16 in) |
| 8″ | 0.198″ (≈ 3/16 in) | 0.09″ (≈ 3/32 in) |
| 10″ | 0.248″ (≈ 1/4 in) | 0.112″ (≈ 1/8 in) |
| 12″ | 0.298″ (≈ 5/16 in) | 0.134″ (≈ 1/8 in) |
| 16″ | 0.397″ (≈ 13/32 in) | 0.179″ (≈ 3/16 in) |
Need a different width or moisture swing? Run the movement calculator preloaded with Pacific Madrone. At a T/R ratio of 2.21, Pacific Madrone is moderately unstable — it moves substantially more tangentially than radially, so flatsawn stock is noticeably cup-prone and quartersawn stock is worth the extra cost in wide panels.
Board footage and weight aren't shown for Pacific Madrone — the Wood Handbook strength tables carry no matched density for it, so a weight figure here would be invented rather than computed. The board foot calculator still works without a species; board feet don't depend on density.
Seasonal movement by city
| City | Driest month (EMC) | Most-humid month (EMC) | EMC swing | 12″ board movement |
|---|---|---|---|---|
| Phoenix, AZ | Jun · 4.4% | Dec · 9% | 4.6 pts | 0.228″ (≈ 7/32 in) |
| Chicago, IL | May · 12.3% | Dec · 15.1% | 2.8 pts | 0.139″ (≈ 1/8 in) |
| Miami, FL | Apr · 12.2% | Sep · 14.4% | 2.2 pts | 0.109″ (≈ 3/32 in) |
| Boston, MA | Apr · 11.5% | Sep · 12.8% | 1.3 pts | 0.064″ (≈ 1/16 in) |
| Denver, CO | Jul · 8% | Dec · 10.5% | 2.5 pts | 0.124″ (≈ 1/8 in) |
| Seattle, WA | Jul · 12% | Dec · 16.9% | 4.9 pts | 0.243″ (≈ 1/4 in) |
Driven by Pacific Madrone's tangential shrinkage of 12.4%. These are outdoor equilibrium-moisture figures, so they are an upper bound — a climate-controlled interior swings less. How this is calculated.
How Pacific Madrone compares
Ranked against the 196 species in the Wood Handbook tables this site carries.
- Stability: its T/R ratio of 2.21 is more even than 16% of the 196 species here — as humidity changes, 84% of them hold their shape more evenly.
Durability & sustainability
CITES status: not listed on any CITES Appendix — no international-trade restriction applies to Pacific Madrone.
Properties
| Specific gravity | — |
|---|---|
| Janka hardness (side) | — |
| Density (air-dry, 12% MC) | — |
| Weight per board foot (air-dry) | — |
| Radial shrinkage (green→oven-dry) | 5.6% |
| Tangential shrinkage (green→oven-dry) | 12.4% |
| Volumetric shrinkage (green→oven-dry) | 18.1% |
| T/R ratio (stability indicator) | 2.2 |
Shrinkage is total green-to-oven-dry (Table 4-3); strength values are at 12% MC. Full bases and the derivation formulas are on the methodology page. Values shown as “—” have no matched entry in the Wood Handbook strength tables (5-3b/5-5b).
Data: USDA Forest Products Laboratory, Wood Handbook FPL-GTR-282 (2021), public domain.