Building Roundwood Trusses
There is a glut of small diameter wood in many parts of the United States, both in national forests and tree farms. This resource is often wasted as it becomes fuel in massive forest fires. On tree farms, where it barely pays the bills, small diameter wood is sold cheaply to make paper. Instead of sending this wood to pulp mills, it could be used to create higher value building materials, including roundwood trusses.

The roundwood truss system described here enables DIYers to build their own trusses at very low cost. Virtually any truss configuration is possible, although roundwood is best suited to simpler designs such as: queen and king post, Fink, Howe, scissor, clerestory, parallel chord, sloping top chord, attic truss (for lofts and second story plans), asymmetric, gambrel and gable end trusses. You can download truss charts off the Internet and use them as guidelines.

Why are trusses so popular? Trusses are prefabricated so they’re ready to install when the walls are finished. This is important for drying in the structure as quickly as possible. Trusses are very strong, efficient and relatively lightweight. They use shorter pieces of wood joined together instead of large dimension lumber. Trusses span longer distances and eliminate the need for center walls or supports.

The downside is factory made trusses use milled wood such as 2x4s to speed construction, but this wood is usually not sustainably harvested and it’s shipped long distances. Both of these practices harm the environment.

Wood in the round is inherently stronger than milled wood and can often be obtained locally at very low cost. The only milling required is where truss members intersect at joints. Coping the end joints will create stronger trusses. You can also flatten the areas around joints on both sides where gussets are attached. You might also want to cut (rip) straight edges on the tops and bottoms of trusses for ease of attaching roofing and ceiling materials, although this isn’t required if you want a rustic look.

If you want straight edges on the tops and bottoms of trusses, crown the poles, snap chalk lines and cut edges with a power saw (Skilsaw, etc.). Use the straightest poles you can find so you don’t remove too much material. A typical 20-foot truss made with 4- to 5-inch diameter poles should have about 4 inches of wood remaining after the rip cut.

owen_1
2/11/2011 7:18:10 PM

I was referring to national forests in the U.S. Just go to the local forest service headquarters and ask for a firewood permit. Sometimes these permits are only offered for certain times of the year, so you'll have to plan ahead.


craiginoxford
2/11/2011 12:38:55 PM

While I Personally wouldnt try to make my own home using home made trusses (Im not that confidant in my "Truss Making" skills...lol) I would like to use them for a good sized storage shed Id like to build.. My question is about this line in the story.. " But you can gather truckloads of poles from national forests, enough for several small houses, for the cost of one firewood permit — somewhere around $25 last time I checked." Can you offer up any info on how to find the wood in these places or who to contact / what to ask for? id love to get some of this wood but dont know the first thing about getting it. Thanks for any advice or info you can provide! Craig in Oxford!





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