Bracing Tips for Pole Barns
Truss bracing isn’t a static decision. The truss span, on center, height, location of large openings, and site conditions all factor in to proper pole barn bracing for trusses.
All pole barns should include purlins connecting truss to truss on the top chord at 24″ on center or less if required by the structural plans.
Just like the purlins connect truss to truss on the top chord, lateral bracing is continuous bracing on the truss bottom chord. This spacing is on your truss drawing and can be from 5′ on center to 10′ on center (typical).
If a truss is tall enough, continuous web bracing will be required as shown on the truss drawing.
Used to ‘cluster’ trusses and support from top to bottom plane. Sway bracing is especially critical for open wall applications (no siding) and where large openings reside. Sway bracing is not continuous like purlins and lateral bracing. It is used as required based upon project conditions.
Here is an extreme example.
70′ 4-12 gable truss 4′ on center 55# ground snow load 110 mph wind
Other Truss Bracing Methods
Cross bracing or X bracing is similar to sway bracing but instead braces from top chord on one side to bottom chord in a criss cross fashion. Also called diagonal bracing.
Wind Bracing involves nailing 2×4’s starting from the post next to the corner post on the eave wall and connecting to the gable endframe truss near the center of the building. The 2×4 is nailed to the bottom of the top chord of the trusses in its path.
We use stub posts to secure trusses between the posts on the truss supports. This is a cheap sturdy way to keep your truss where you want it to be and keep it plumb during construction.
Pole Barn Wall Bracing
A post frame building with steel siding and roofing fastened @ 24″ on center creates a diaphragm effect affording substantial strength to your building.
The same building with sheathing and Hardie board is quite strong as well due to the sheathing.
The same building with board and batten siding would need much more bracing than the two examples above.
Corner braces are critical for tall buildings. A 10′ wall with 4′ of post in the ground requires less of corner braces than the taller structures. Most builders omit corner braces below 10′ but we include them in all packages.
If wind speed, wall height, and post spacing dictate we include girt stiffeners in our pole building kits to create our stout wall system.
This is simply a 2×6 turned strong and fit between the truss supports and nailed to each girt, truss supports, and grade board. No more wall flapping in 100 mph winds!
No siding on your building means it will be more susceptible to racking under extreme conditions compared to an enclosed building. Knee braces are used to support the trusses and keep things in alignment. A 2×6 is nailed on the notched side of the post where the truss sits so the brace lines up with the truss and post for nailing.