Trusses: often spaced 4’ to 10’ on-center, trusses may spaced the same as and attached directly to the post, or spaced differently than the post and attached to a truss carrier beam that spans between the post. In weight bearing cases (where a truss is not attached directly to a post) the girt acts as a beam and often labeled as a “truss carrier”. Top Girt/Truss Carrier: Highest girt from ground level. Spacing is usually no further than 2’ on-center. Girts are perpendicular to post and may be installed upright on the face of the post, or turned flat (bookshelf) between the post. Girt: 2x4 or 2圆 horizontal framing member nailed from post to post. If steel siding is fastened directly to the treated skirt board, a barrier of: building felt, house wrap, window wrap or other non-metal flashing is recommended between the two. The bottom of any siding or wall sheathing will be attached to this. Skirt Board: (also Splash Board or Grade Board) The bottom wall girt, may be one or more rows of treated 2圆, 2x8, center-match (T&G 2x_) or composition lumber rated for ground contact. Building size, height and other load factors will determine the pad size required, but generally the depth of the pad is 1/2 the diameter of the pad.

All concrete footers should be mixed with clean water outside of the hole, and set before the post is placed.

Post Footing: Concrete footer pads, usually 18”-24”, are placed at the bottom of the hole below the wood post. Embedded precast concrete piers or specially designed wood-to-concrete steel brackets are an alternate to installing the wood post below grade. Post may use 2x4 treated wood cleats nailed at the bottom of the post, concrete collars, rebar rods, or other anchors to provide uplift resistance. These are set in the ground a minimum of 1/4 its’ length, and at least 4’. Post sizes are often 4圆, 6圆, 6x8, 8x8 or as required by design. Posts: Treated solid-sawn post or glue or nail-laminated columns. “Galvanized Pole Barn Nails” are hardened spiral or ring shank nails for load-bearing wooden structures where superior holding power is necessary. Your building, however, may require 5/8”, 3/4” or larger bolts to attach the truss to the post. The exception: bolts in contact with treated lumber need not be hot-dipped galvanized, but must be at least 1/2” thick. Aluminum fasteners should not be used with copper based treated lumber. For best results, use the same type of metal for fasters as the metal siding and trim: Hot Dipped Galvanized fasteners for Galvanized and Aluminum-Zinc Alloy metal, Copper fasteners for copper metal, and stainless steel for all metals including those at or below ground level. Stainless steel or hot-dipped zinc-coated galvanized steel are often used with treated lumber. Treated lumber installed higher than 18” above ground may be a lower retention.įasteners: Fasteners used with treated lumber should be corrosive resistant. 2”x_ skirt board or any board in contact with the ground should have a min. ACQ or CCA post should have a minimum preservative retention level of. CCA treatment may be used on lumber 5”x5” and larger posts in Post-Frame building use, but may not be permitted for residential decks, gazebos or playground equipment. Common preservatives are Alkaline Copper Quaternary (ACQ), Copper Azole (CA) and Chromated Copper Arsenate (CCA). Generally, any lumber within 18” from the ground should be treated. Pressure Treated Lumber: Treated lumber is primarily used for skirt boards and post. Post Frame buildings may often be built where “Pole Barns” are not permitted or zoned for. Pole Buildings use round poles whereas Post Frame Buildings use square or rectangular post, commonly 4x4, 4圆, 5x5, 6圆 or larger treated lumber or laminated columns. Pole Barn: The term “Pole Barn” is often used in place of “Post Frame” however there is a distinction between the two.

Rafter spacing for pole barn metal roof