Every coop we sell is framed with 2x4 walls on 16-inch centers, 2x6 floor joists on 16-inch centers, 2x6 or 2x8 rafters, and 4x4 only where lumber touches the ground or carries the corners. A 4x4 wall frame would double the lumber in the studs, and nothing in our plans needs it, which is the short answer to the question people type into Google.
The longer answer is in the cut lists. Every cut list on this site is a framing document, so this page pulls the real numbers from two of them, the 4x6 and the 8x12 walk-in with feed room, and explains why each member is the size it is. Where a number is our design choice, it says so.
2x4 or 4x4 for the main frame
The 4x4 pieces in our plans are the four corner posts (64-3/4 in on the 4x6, 98-3/4 in on the 8x12), the base ring tying them together at grade, and the run posts. Everything above the floor is 2x4.
Count what you would be doubling. The 4x6 walls take 29 vertical studs (common, king and jack) totaling about 81 linear feet. In 2x4 that is roughly 54 board feet, nominal. In 4x4 it is 107. The 8x12 takes 47 vertical studs, 280 linear feet: about 187 board feet in 2x4 and 373 in 4x4. That is nearly 190 more board feet of lumber for one coop.
On the structural side, the members that bend are the ones the plans check against published tables: the floor joists and the rafters. Studs in a coop wall hold up a light roof and are tied by three plates per wall. The plans never call for more than a 2x4 stud. We do not publish a stud table, so if you build taller than 76 in or hang a heavy roof, check your local code’s stud table first.
Skids, posts or blocks
The plans use three foundations, and the choice follows what the coop does.
Posts on pier blocks carry every walk-in and shed coop. Four 4x4 posts stand on solid concrete deck blocks, each on compacted 3/4-in gravel, and the floor frame hangs 12 to 24 in above grade depending on the design: 12 in on the walk-ins, 14 on the 4x8s, 18 on the 4x4 and 4x6, 20 on the 6x8 chicken coop and 24 on the 8x12 chicken coop. That keeps the frame out of ground moisture and leaves shade under the coop. The 4x6 uses 10 blocks, the 8x12 uses 14.
Skids carry the A-frames. The tractors use 2x4 skids on edge and the fixed 6x8 A-frame uses pressure-treated 4x4 skids on six blocks, each on 6 in of crushed stone. A skid is a floor frame that can drag. See the A-frame plans for how the rafters and base tie together.
Buried posts carry the runs: 4x4 rated for ground contact, 96 in long, set about 4 ft apart.
Every height in a plan is measured from the top of the pier block, not the soil. Set the blocks first, level them to a string line, and call that plane zero.
The floor frame
The 8x12 floor is ten 2x6 joists, 90 in long, on 16-in centers inside a doubled 2x6 rim. The plan frames them to AWC’s published deck table, which allows 8 ft 4 in for a 2x6 at 16 in on center, so a 90-in span has room to spare and no girder is needed. We have not re-checked that table this session and the plan text is where the figure comes from.
Past that span a girder appears. The 10x10 runs 114-in joists, over the table’s 100 in, so it adds a doubled 2x6 girder on four short 4x4 posts at 40 in, which cuts each joist’s clear span to 57 in. The 4x6 is the other end: six 42-in joists.
The rim sits on the base ring and closes the outside face of each post, fastened with two 4-in structural screws per corner, one near the top of the rim and one near the bottom, offset and predrilled. The deck is 3/4-in plywood notched 3-1/2 in at each corner, screwed with 1-1/2-in screws every 8 in on the joists.
The wall frame, in order
Every wall is framed flat on the deck and then stood: front wall, back wall, then the two end walls, so the short walls have something to brace against. Studs run 16 in on center, which also lets 4-ft sheet goods break on a stud. Each wall gets three plates: bottom, top and a cap plate. The cap is not for strength. It laps the corner: long walls’ caps stop 1-1/2 in short at both ends, end walls’ run 1-1/2 in long, so the corners interlock instead of butting.
The bottom plate runs continuous through door openings and is cut out with a handsaw after the wall is standing, because the plate keeps the wall square while you move it. Headers are two 2x4s with a 1/2-in plywood spacer between, which makes 3-1/2 in, flush on both faces; the 8x12’s back wall carries a pair of 2x8s over the 74-1/2 in nest opening.
Openings drive the count more than the walls do. In the 8x12, 19 of the vertical studs are common studs and 28 are king and jack studs framing windows and doors. In the 4x6, it is 9 against 20.
Sheathing and fasteners
The standard plans do not sheath the walls. Lap siding goes on the studs, and the 3/4-in plywood is the floor deck, roof deck, door slabs and nest parts; 1/2 in is for header spacers and the feed-room partition. The one exception is the 8x12 insulated coop, which adds 11 sheets of 7/16-in OSB wall sheathing under the siding and a 1/2-in plywood interior liner. For the roof, see the chicken coop roof guide.
The fastener list on the 8x12 is short: four boxes of 2-1/2-in exterior screws, two of 1-1/2-in, 24 four-inch structural screws for the base ring and posts, eight 3/8 by 4 in lag bolts that tie the run rails to the coop’s corner posts (two per rail, not into siding), and 280 neoprene-washer roof screws across seven panels. Siding is a skin; it holds nothing, so the run is lagged to framing.
How it changes by size
| 4x6 | 8x12 walk-in | 10x10 walk-in | |
|---|---|---|---|
| Stud height | 36 in | 76 in | 76 in |
| Vertical studs | 29 | 47 | 46 |
| Floor | 6 joists, 42 in | 10 joists, 90 in | 9 joists, 114 in + girder |
| Roof | 12:12 gable, 2x4 rafters, ties | 3:12 shed, 2x6 rafters at 24 in | 3:12 shed, 2x8 rafters at 24 in |
| Pier blocks | 10 | 14 | 16 |
The how-to-build guide walks the build order, and the materials guide covers grades and prices.