Ipe wood movement, board-foot & weight calculator
- Janka
- 3,680lbf
- Density
- 64.3lb/ft³
- T/R ratio
- 1.2
- Spec. gravity
- 0.92
Ipe (Tabebuia spp.) is an imported species. It has a Janka side hardness of 3,680 lbf, a specific gravity of 0.92, and an air-dry density near 64 lb/ft³ (1,030 kg/m³) (mechanical values at 12% moisture content). It shrinks 8% tangentially and 6.6% radially from green to oven-dry (T/R ratio 1.2), so a 12-inch flatsawn board moves about 0.19 in (≈ 3/16 in) across a 6-point moisture swing (about 6%→12% MC).
Compute Ipe: movement, weight & board footage
Every number below is worked from Ipe'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″ | 0.032″ (≈ 1/32 in) | 0.026″ (≈ 1/32 in) |
| 3″ | 0.048″ (≈ 1/16 in) | 0.04″ (≈ 1/32 in) |
| 4″ | 0.064″ (≈ 1/16 in) | 0.053″ (≈ 1/16 in) |
| 6″ | 0.096″ (≈ 3/32 in) | 0.079″ (≈ 3/32 in) |
| 8″ | 0.128″ (≈ 1/8 in) | 0.106″ (≈ 3/32 in) |
| 10″ | 0.16″ (≈ 5/32 in) | 0.132″ (≈ 1/8 in) |
| 12″ | 0.192″ (≈ 3/16 in) | 0.158″ (≈ 5/32 in) |
| 16″ | 0.256″ (≈ 1/4 in) | 0.211″ (≈ 7/32 in) |
Need a different width or moisture swing? Run the movement calculator preloaded with Ipe. At a T/R ratio of 1.21, Ipe is very stable — it moves almost as much radially as tangentially, so flatsawn boards have little reason to cup and wide panels stay flat with ordinary care.
Board footage & weight, standard sizes
| Nominal size × length | Board feet | Weight |
|---|---|---|
| 1×4 × 8′ | 2.67 bd ft | 14.3 lb |
| 1×6 × 8′ | 4 bd ft | 21.4 lb |
| 1×8 × 8′ | 5.33 bd ft | 28.6 lb |
| 1×10 × 8′ | 6.67 bd ft | 35.7 lb |
| 1×12 × 8′ | 8 bd ft | 42.9 lb |
| 2×4 × 8′ | 5.33 bd ft | 28.6 lb |
| 2×6 × 8′ | 8 bd ft | 42.9 lb |
| 2×8 × 8′ | 10.67 bd ft | 57.2 lb |
Different length or size? Run the board foot calculator or the weight calculator, both preloaded with Ipe.
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 | 0.147″ (≈ 5/32 in) |
| Chicago, IL | May · 12.3% | Dec · 15.1% | 2.8 pts | 0.09″ (≈ 3/32 in) |
| Miami, FL | Apr · 12.2% | Sep · 14.4% | 2.2 pts | 0.07″ (≈ 1/16 in) |
| Boston, MA | Apr · 11.5% | Sep · 12.8% | 1.3 pts | 0.042″ (≈ 1/32 in) |
| Denver, CO | Jul · 8% | Dec · 10.5% | 2.5 pts | 0.08″ (≈ 3/32 in) |
| Seattle, WA | Jul · 12% | Dec · 16.9% | 4.9 pts | 0.157″ (≈ 5/32 in) |
Driven by Ipe's tangential shrinkage of 8%. These are outdoor equilibrium-moisture figures, so they are an upper bound — a climate-controlled interior swings less. How this is calculated.
How Ipe compares
Ranked against the 196 species in the Wood Handbook tables this site carries.
- Hardness: at 3,680 lbf, Ipe is harder than 99% of the 157 species with a Janka figure — firmly in the hard quarter, which is what resists denting in flooring and worktops.
- Weight: at 64.3 lb/ft³ it is heavier than 98% of the 170 species measured — an 8-foot 1×6 board weighs about 21.4 lb.
- Stability: its T/R ratio of 1.21 is more even than 98% of the 196 species here — as humidity changes, 2% of them hold their shape more evenly.
See Ipe plotted against every species we carry: the full Janka hardness chart and the full density chart .
About Ipe
Ipe, the common name for the lapacho group of the genus Handroanthus, consists of about 20 species of trees that occur in practically every Latin America country except Chile. Other commonly used names are guayacan and lapacho. Sapwood is relatively wide, yellowish gray or gray–brown, and sharply differentiated from heartwood, which is light to dark olive brown. The texture is fine to medium. The grain is straight to very irregular and often narrowly interlocked. The wood is very heavy and averages about 1,025 kg m–3 (64 lb ft–3) at 12% moisture content. Thoroughly air-dried heartwood specimens generally sink in water. Because of its high density and hardness, ipe is moderately difficult to machine, but glassy smooth surfaces can be produced. Ipe is very strong; in the air-dried condition, it is comparable with greenheart (Chlorocardium rodiei). Hardness is two to three times that of white oak (Quercus alba) or keruing (Dipterocarpus). The wood is highly resistant to decay and insects, including both subterranean and dry-wood termites, but susceptible to marine borer attack. The heartwood is impermeable, but the sapwood can be readily treated with preservatives. Ipe is used almost exclusively for heavy-duty and durable construction. Because of its hardness and good dimensional stability, it is particularly well suited for heavy-duty flooring in trucks and boxcars. It is also used for decks, railroad crossties, turnery, tool handles, decorative veneers, and some specialty items in textile mills.
Properties
| Specific gravity | 0.92 |
|---|---|
| Janka hardness (side) | 3,680 lbf |
| Density (air-dry, 12% MC) | 64.3 lb/ft³ (1,030 kg/m³) ovendry-weight basis: 57.4 lb/ft³ |
| Weight per board foot (air-dry) | 5.36 lb |
| Radial shrinkage (green→oven-dry) | 6.6% |
| Tangential shrinkage (green→oven-dry) | 8% |
| Volumetric shrinkage (green→oven-dry) | 13.2% |
| T/R ratio (stability indicator) | 1.2 |
Shrinkage is total green-to-oven-dry (Table 4-4); strength values are at 12% MC. Full bases and the derivation formulas are on the methodology page.
Data: USDA Forest Products Laboratory, Wood Handbook FPL-GTR-282 (2021), public domain.