COVER Timberworks uses #1 or better Free of Heart Center Coastal Douglas Fir for its outdoor timber frame shade structures. Douglas Fir is one of the most widely used species in timber frame construction because it offers an excellent combination of strength, density, stability, and appearance.
For structural pergolas, pavilions, and other outdoor timber frame shade structures, Douglas Fir has several advantages:
- Proven structural performance
Douglas Fir is commonly used in timber frame homes, pavilions, pergolas, and other exposed structural applications because of its strong engineering properties. - Greater density than many common softwoods
Douglas Fir is denser than many alternative species used in outdoor structures. For example, it generally weighs 40 percent or more than cedar, giving it a stronger and more substantial feel. - Strength for larger spans and roofed structures
That added density contributes to higher strength values, helping Douglas Fir perform well in posts, beams, rafters, braces, trusses, and larger open span designs. - Improved stability with Free of Heart Center material
Free of Heart Center timber is cut to exclude the center pith of the tree, which helps reduce the severity of checking, twisting, and movement. Combined with the natural density of Douglas Fir, this creates a more stable timber for exterior structural use. - A preferred species for premium timber framing
Architects, engineers, and timber frame builders often specify Douglas Fir when they want a structural timber that balances strength, appearance, workability, and long term performance.
Some surface checking is still normal in exterior timber because wood expands and contracts with sun, heat, humidity, and weather. The goal is not to make wood behave like plastic; it is to use a high quality timber that performs well structurally, finishes beautifully, and has the scale expected in a premium outdoor structure.
Timber selection also varies by line, and the Summit Series uses a value focused timber package.













