Wood - Compressive Strength vs. Moisture Content
Red Spruce, Longleaf Pine and Douglas Fir - moisture content and their compressive strength.
Moisture content influence compressive (parallel to grain) strength of Red Spruce, Longleaf Pine and Douglas Fir:
Indicated strengths are relative to wood containing 2% moisture.
- Red Spruce - air dried : 14% moisture content, kiln dried : 6% moisture content
- Longleaf Pine - green wood : 20 % moisture content
- Douglas Fir - green wood : 24 % moisture content
Example - Compressive Strength of Moist Spruce
The compressive strenght of spruce is normally in the range 18 - 39 MPa (2610 - 5655 psi). The diagram above indicatees that maximum strengt is reduced to 50% for spruce with 16% moisture. The reduced range can be calculated as
[18 - 39 MPa (2610 - 5655 psi)] * 0.5
= 9 - 19.5 MPa (1305 - 2828 psi)