Lumber, Trusses & Post Engineering For Pole Barns
Burrow’s Post Frame Supply helps builders secure lumber, trusses, and post engineering supplies for their next pole barn or post frame structure.
Mills are usually associated with one of two inspection agencies. They are the Southern Pine Inspection Bureau(SPIB) and Timber Products Inspection(TPI). Grading by these authorities is fairly uniform with respect to such criteria as wane, knot size, checking, and skip. SPIB and TPI grade stamps include a mill number to identify where the lumber was produced.
What you want to stay away from is mill grade lumber where an individual mill owner determines his own grading system.
Better Buildings Start With Better Materials
- Grading can get confusing due to the different types of wood sources. For example, a number 2 grade of Douglas Fir has the same strength as the number 3 grade of Southern Yellow Pine.
- Wood trusses are engineered based on load factors as well as structural design. We provide professional builders drawings of our trusses with an engineer’s stamp.
- Wind loads and snow loads vary by location. For Iowa, our trusses are built for 30-pound snow laid, and a 90 MPH wind load. In Oklahoma, that truss will be built for a 20-pound snow load and a 90 MPH wind laid. And for hurricane threatened south Texas, we build trusses for 20-pound snow load and a 120 MPH wind load.
- Be sure your builder knows how you plan to finish the building, as this can impact truss load. For example, you may have it in mind to install a ceiling later, and that can add a significant load to the bottom chord of your trusses.
- Burrow’s sponsored a recent survey, asking post-frame builders across the country what types of posts were most common in their areas. Of the 134 builders who answered this question, 44% said solid sawn, followed by 27.6% saying nailed laminated, and 26.9% saying glue-laminated.
Bonus Tip: We may on occasion advise that glue-laminated posts are ideal, but for most projects, what is your best value? A 12” tall sidewall with posts on 8’ centers in terrain exposure “b” (urban, suburban, and wooded areas) is typical. For this application, an independent engineer attested in writing that our 3-ply 2×6 un-spliced nail laminated posts are good for up to 146 mph wind loads; that our 4-ply 2×6 nail laminated posts are good for up to 169 mph wind loads; and that our 3-ply 2×8’s are good for up to 208 mphBack To Blog