Turns out Douglas fir is more than just a good-looking wood. Its durability and resistance to rot and insects make it a favorite choice for outdoor projects like porch decking as well. It’s also naturally resistant to rot, decay, and insects.Click to see full answer. Similarly one may ask, do you need to treat Douglas fir?It’s naturally durable so is good for use externally and will fare better than other softwoods in the ground and if it’s not being used as a fencepost (!… time we got some new timber durability classifications!) then it doesn’t need treatment.Likewise, what is the best wood for outdoor use? 9 Wood Species Best for Outdoor Projects Acacia. Acacia is a thick, strong hardwood with high oil content. Black Locust. Black Locust is one of the strongest and stiffest domestic woods. Cedar. Cedar is soft, light, and easy to work with. Cypress. Cypress wood is rot and insect resistant attributable to its natural oils. Douglas-Fir. Ipe. Redwood. Teak. Moreover, how do I protect my Douglas fir outside? Sealing with wax and tar are other traditional methods for preserving and “waterproofing” wood that have been used with fir. In most home uses, a coat of oil bonding primer and two coats of latex paint, or two coats of exterior grade stain and clear finish, are sufficient to waterproof the surface.What is Douglas fir used for?Structurally, it is used in the form of lumber, timbers, pilings and plywood. Douglas-fir is also used to produce a wide variety of products including general millwork, flooring, furniture, cabinets and veneer. This species has excellent strength properties and is well known for its workability.