What is small diameter round-timber?
WholeTrees uses whole diameter tree trunks (4 inches to 20 inches) and unwanted branched timbers that would otherwise be removed from routine forest thinning (such as suppressed, fallen, diseased, invasive or wind-bent trees) to create structural solutions for commercial and residential buildings.
Advantages of WholeTrees structural solutions over milled lumber:
- Round-timber is 50 percent stronger in bending strength than comparably sized squared timbers, according to the USDA Forest Products Laboratory – Forest Service.
- Round-timber uses less than one-fifth of the energy required to make conventional lumber.
- Milling typically removes the strongest outer layers of the tree, which are naturally pre-tensioned to resist wind shear.
- Round-timber has increased fire resistance, charring at 1.5 inches per hour, as well as low embodied energy and carbon sequestration at 50 percent of dry weight.
Advantages of WholeTrees over steel and concrete:
- Life cycle assessment (LCA) studies show that wood outperforms fossil fuel-intensive materials, such as steel and concrete on all measures, including embodied energy, air, water pollution and global warming.
- Round-timber requires less than two percent of the energy of concrete and steel materials for processing and transportation.
- In fire, round-timber chars instead of burning or melting, with higher fire resistance than unprotected steel, according to the USDA Forest Products Laboratory – Forest Service.
Cost advantages of WholeTrees and round-timber:
- Wood structures have lower material and construction costs than steel or concrete.
- Unlike steel, material costs for round-timber are more stable and WholeTrees quotes projects with a 12-month or longer price guarantee.
- Round-timber typically costs less to install than other materials and is more lightweight, reducing the need for foundation capacity.
- Engineering the trees:
In partnership with the USDA Forest Products Laboratory – Forest Service, WholeTrees has paired empirical data from its existing projects to leverage the innate structural engineering of trees. Research allows WholeTrees to apply design values to small diameter round-timber, work with structural engineers to optimize commercial structural systems and give architects the stamped structural systems they need to specify WholeTrees products in commercial applications.
WholeTrees products help earn points in green building rating systems, including up to 10 LEED points (v 4.0), and comply with international and state building codes.
Studies show that natural elements, such as wood, located in work and public spaces—an experience known as biophillia—improves the quality of life of occupants by reducing stress and boosting employee or customer morale.
WholeTrees structures are made from a wide variety of species, including black locust for exterior applications and white oak and red pine for interior spaces. Typical column/truss assemblies include straight and branched columns, beams, joists, rafters and trusses for standardized and customized solutions. WholeTrees structures are treated with safe and effective compounds to eliminate pests and reduce the risk of moisture.