Pole Barn Trusses
Roof trusses are a very important component in any structure. We have our own truss plant where we design and build pole barn trusses for all the DIY pole barn kits we supply. We design our pole barn trusses right here which means we are not relying on a third party to tell us what we need.
We use a standard agricultural loading of 25-5-2 for all of our standard pole barn trusses. These numbers are in a PSF format (pounds per square foot). These numbers very well could change depending on the municipality you live in. The 25 stands for the roof live/snow load. This is the standard load for central Ohio. Typically the farther north you travel, and areas with heavier snow fall this number should start to go up. If you are not sure what your live/snow load is contact your local building department. This is a common question for them and can usually tell you right over the phone. The 2nd number is a 5, the 5 stands for the roof dead load (materials that are there to stay). In our case this would be wood purlins spaced 24 inch on center, single bubble vapor barrier and metal roofing. This number would only change if your municipality would require a heavier load. The 3rd number is a 2, the 2 stands for the ceiling dead load (materials hanging from the trusses). In our case this would be an open or unfinished ceiling.
If you wish to finish your ceiling off with metal or gypsum board and pole barn insulation we would need to put a heavier load on the bottom chord of the truss. For a metal ceiling with pole barn insulation we recommend a 5 psf load. For gypsum board and pole barn insulation we recommend a 10psf load. These are the loads we use, however we always recommend that you check with your building department to ensure they do not require something different.
Our pole barn trusses are engineered to be placed 48 inch O.C. (on center spacing). Beware of kits that space their pole barn trusses over 48 inch O.C. These pole barn trusses are much harder to set in place, and the further spacing can displace loads causing the trusses to fail. One sign of a cheap pole barn is the trusses are spaced over 48 inch O.C.