Choosing the right species for your outdoor project will affect not only the appearance of the finished product, but may affect the structural integrity and lifespan, especially for outdoor projects like pergolas, trellises and pavilions. • The 4 factors to consider are: o Structural integrity and design ▪ If your project has long open spans, it’s important to realize that some species are much stronger than others.  For example, Douglas Fir is 40% stronger than Western Red Cedar.  This means that spans in your pergola or pavilion done with Douglas Fir will not sag over time if sized properly.  Western Red Cedar is not a structural species, and has no span tables to refer to for sizing, but if Doug Fir will carry 1,000 lbs in a given application, the same size timber in Cedar will only carry 600 lbs. o Resistance to rot and insect infestation ▪ In the past, Redwood has been considered the benchmark species for outdoor projects.  All Heart Redwood is a great resister of insect and rot, but it’s become prohibitively expensive and difficult to find in certain sizes and grades. ▪ Cedar has also enjoyed a reputation as a species that resists insects and rot, but the quality of Cedar is not what it used to be.  If you’ve ever had a Cedar privacy fence, you know from the condition of the wood where it contacts the ground, Cedar is not impervious to insects or rot. ▪ In tests over a span of more than 20 years, the US Forest Service found that Douglas Fir and Western Red Cedar Heartwoods were comparable in longevity, and Douglas Fir Sapwoods out performed Western Red Cedar Sapwoods by 36%.  The results are shown in Table 1 here. o Appearance ▪ Typically, for less money you will get a higher grade of Douglas Fir than you will Cedar, and Fir can be readily purchased with an FOHC specification that will reduce rot and infestation. o Maintenance: All species used in open applications should be treated and maintained with a good quality penetrating oil.  Additional Pigment will aid in protecting the wood from harmful UV rays.