The Paulownia field guide · Chapter 4
Chapter 4Timber
The wood
Paulownia lumber is about 40% the weight of red oak and roughly twice as dense as balsa, which makes it one of the lightest commercial hardwoods. It is pale blond, fine grained, and very stable once dry, so it warps little. It cuts, nails, glues, and finishes easily.
| Property | Paulownia | Notes |
|---|---|---|
| Density, air-dry | 16 to 20 lb/ft³ | 260 to 320 kg/m³ |
| Shrinkage, green to dry | 2.4% radial, 3.9% tangential | Very low. High dimensional stability. |
| Modulus of rupture | ~5,500 psi | About 38 MPa. Red oak is about 14,400 psi. |
| Modulus of elasticity | 0.4 to 0.7 Mpsi | About 2.7 to 4.9 GPa |
| Compression parallel to grain | ~3,000 psi | About 21 MPa |
| Fire behavior | Flame resistant for its weight | Lab tests found better flame retardancy than cedar. |
Values are typical for plantation Paulownia and vary with species, age, and growing conditions. Published figures are often measured on P. tomentosa. Full references on the Sources page.
Color ages from pale blond to a warm honey tone. In Japan it has long been used for kimono chests, valued for its light weight and stability in humid weather.