Pole barn kits · 30 × 40
30x40 Pole Barn Kit: What's In It, How Many Posts, Starting Price
A 30 by 40 is the most-searched pole barn size in the country and the most common one we sell. It covers 1,200 sq ft: two trucks and a workbench, a tractor and implements, or hay for a small herd. Here is exactly what the kit includes, how it lays out, and how to get your exact delivered price.
Pole barn kit pricing
Materials only, 26 ga Galvalume, posts and trim included. Configure your building, verify your phone by text, and see your exact delivered price instantly — one total, good for one week. Delivery: $200 within 120 miles of our yard, $285 beyond, final delivery cost confirmed at order based on location.
How a 30x40 lays out
Forty feet of length divides into three bays of roughly 13 ft 4 in. That puts a steel truss at each end and two in the field: four truss lines, eight posts, one under each end of each truss. At 13 ft 4 in the bays sit inside the 15 ft limit for 4 in C-purlin, and the configurator prices the purlin section that comes out cheapest for the run.
Each 30 ft truss carries two slopes of about 15 ft 10 in of rafter length at 4/12 pitch; with the 16 in overhang the roof panels cut to roughly 17 ft. Purlin rows run the full 40 ft on each slope at no more than 48 in on center, so you get five rows per side. Ridge cap covers the peak and rake trim finishes both gable ends.
The standard eave is 12 ft, which clears a pickup with a rack or a tractor with a cab. Drop to 10 ft for a hay barn or equipment cover and the posts get shorter and cheaper. Go to 14 ft for an RV or a lift and the configurator moves to 6x6x20 posts. Above 15 ft eave it moves to 8x8x20.
How PRC sizes a kit
- Trusses: 4/12-pitch steel web trusses matched to the width, one at every truss line including both ends.
- Posts: treated 6x6x16 to a 13 ft eave, 6x6x20 to a 15 ft eave, 8x8x20 above that. Two bags of concrete per post. One post under each end of each truss.
- Bays: the space between truss lines. Bays up to 15 ft use 4 in C-purlin; bays up to 20 ft use 6 in. 8 in purlin is never used on trusses. The configurator picks the lower-cost combination for your length.
- Purlin rows: never farther apart than 48 in on center, running the full length of the building on each slope.
- Roof: 26 ga ribbed metal panels, 36 in coverage, cut to the slope length with a 16 in framing overhang. Galvalume (25-year finish) or White SMP (45-year finish). 29 ga available.
- Trim and hardware: ridge cap and gable rake trim in 10 ft 2 in pieces, truss-center and truss-to-post bolt sets, washer screws by the 250-count bag.
Working rules used by PRC to count materials, not an engineering design. Your permit office may require sealed drawings; see the permit note on the pole barn kits page.
What a 30x40 kit does not include
This is an open, roof-only post-frame kit. It does not include a concrete slab, sidewall or endwall panels, wall girts, doors, windows, insulation, gutters, engineering or permits. Enclosure is a common add: tell us in the configurator notes and we will quote wall panels and girts with the kit. Many buyers pour the slab after the roof is up so they work in the shade.
Installed, or build it yourself
Toggle "Installed by a PRC crew" in the configurator. Installed price shown as an estimate, confirmed after a site visit. Our crews are vetted and insured and work across Mississippi, Louisiana, Alabama and Texas. If you are building it yourself, the kit arrives with a counted materials list, and a 30x40 is a realistic size for two or three people with equipment to handle the trusses. See install crews.
30x40 pole barn questions
How many posts for a 30x40 pole barn?
Eight, in the PRC layout: four truss lines (two ends plus two in the field) with a post under each end of each truss. Builders using wood trusses on 8 to 12 ft spacing use more posts, which is one reason steel web truss kits price well at this size.
How much does a 30x40 pole barn kit cost?
Pole barn kits start at the figure shown above. For your exact 30x40: Configure your building, verify your phone by text, and see your exact delivered price instantly — one total, good for one week. Delivery: $200 within 120 miles of our yard, $285 beyond, final delivery cost confirmed at order based on location. Installation is a separate line.
Is building a 30x40 pole barn easy?
It is one of the more approachable buildings an owner can put up. No foundation forms, no stud walls, no decking. The work is setting eight posts plumb and on layout, lifting four trusses safely, and screwing down purlins and panels at height. With a tractor or telehandler and two or three people, a few working days is realistic.
What eave height should I pick?
10 ft for hay and implements, 12 ft for trucks and most shop use, 14 ft for RVs, a lift or a combine. Each step up adds post length and a little panel length; the configurator reprices instantly.
Can I add covered space off the end later?
Yes. A gable extension kit runs a covered roof straight out from the gable end of your barn, following the same pitch, without touching the existing trusses.
Pole barn vs metal building for a 30x40, which is cheaper?
For an open roof structure, the post-frame kit wins on materials and on foundation, since the posts are the foundation. Read the full comparison.
Related
All pole barn kit sizes · 40x60 pole barn kit · C purlin prices and spacing · 26 vs 29 gauge roofing · Mississippi · Louisiana · Alabama · Texas
See your exact delivered price
Configure your building, verify your phone by text, and see your exact delivered price instantly — one total, good for one week.