8x12 Lean-To Shed Material List: Lumber, Sheets, Hardware

Last updated October 13, 2026

Our 8×12 lean-to shed material list, for a shed on skids, comes to 61 2×4 framing boards, 12 treated 2x6s and 3 treated 4×4 skids. Sheets: 3 floor plywood, 5 OSB and 12 T1-11, plus 5 shingle bundles. That assumes an 80 in back wall, a 103 1/8 in front wall and a 3/12 roof with 2×4 rafters.

Every count and cut length here comes from the 3DSHEDPLANS plan generator, which frames the shed stud by stud and then counts boards by the stock lengths a lumber yard sells. This list is for a freestanding shed; for one built against a wall, see lean-to shed against a house.

What this 8×12 lean-to list assumes

The generator ran a shed 8 ft deep and 12 ft wide, with 96 sq ft of floor. The roof slopes front to back, so the 12 ft front wall with the door is the tall one. These are its settings:

• Walls: the back (low) wall is 80 in tall and the front (high) wall is 103 1/8 in, both including the bottom plate and double top plate. Back studs are 6′ 3 1/2″ and front studs 8′ 2 5/8″.
• Roof: 3/12 pitch (about 14 degrees), 2×4 rafters with a birdsmouth on both walls, 8 in overhangs front and back, 4 in rakes. The roof is 152 in long by about 115 in down the slope, roughly 122 sq ft.
• Spacing: studs, floor joists and rafters at 16 in on center.
• Floor: three pressure-treated 4×4 skids on a crushed stone pad, 2×6 joists across the 8 ft depth, 3/4 in tongue and groove plywood.
• Loads: the 2×4 rafters span 89 in against the 98 in the generator allows for a 2×4 (span table values for SPF #2 at 16 in, 30 psf ground snow). If your ground snow load is over 30 psf, check your local permit office before you buy rafters.
• Openings: a 60 in double door in the front wall and one 36 x 36 in window in the back wall.

Shopping list by stage: the full 8×12 lean-to shed material list

Lumber sizes are nominal. A 2×4 measures about 1 1/2 x 3 1/2 in and a 2×6 about 1 1/2 x 5 1/2 in, as the American Wood Council explains. Check the grade stamp on plywood and OSB; the APA trademark guide shows how to read it.

Floor

Item	Qty	Used for
Pressure-treated 4×4 x 12 ft	3	Skids
Pressure-treated 2×6 x 12 ft	2	Rim joists
Pressure-treated 2×6 x 8 ft	10	Floor joists
3/4 in T&G plywood, 4×8 sheet	3	Floor decking
Crushed stone 3/4 in, loose	2.1 cu yd	Gravel pad
Deck screws 2 in (or 6d ring-shank nails)	3 lb	Decking

Walls

Item	Qty	Used for
2×4 x 8 ft	19	Five shorter side-wall stud lengths, side-wall plates, sloped top plates, cripples, back sill, rafter blocking and lookout blocks
2×4 x 10 ft	16	10 front wall studs, the 4 tallest side-wall studs and rafter blocking
2×4 x 12 ft	7	Front and back plates and cap plates, back window trimmers
2×4 x 14 ft	7	12 back wall studs (two per board), front door trimmers
2×8 x 12 ft	1	Door header
2×6 x 8 ft	1	Window header
Strap ties (twist straps)	4	One per corner, where a sloped side plate meets the front or back wall
Temporary braces 2×4 x 12 ft	8	Wall bracing, reused later
2×4 stakes, about 21 in	8	Brace stakes, cut from front-stud offcuts (not a separate buy)

The two header filler strips of 1/2 in plywood are ripped from the soffit sheet, so buy that sheet with the wall lumber. The list has 28 2×4 x 10 ft boards in all; 12 of them are the rafter stock in the roof table below. With the 8 braces, the truck carries 69 2x4s.

Roof

Item	Qty	Used for
2×4 x 10 ft	12	10 rafters and 2 fly rafters
Hurricane ties, H2.5A type or equal	20	Rafter to plate, both walls
7/16 in OSB, 4×8 sheet	5	Roof sheathing
15 lb felt, 400 sq ft roll	1	Underlayment, laid double below 4/12
3-tab shingles, 26 per bundle	5 bundles	Roof and starter course
Drip edge, 10 ft	5	Eaves and rakes
Roofing nails 1 1/4 in galvanized	5 lb	Shingles
Roofing cap nails 1 in	1 lb	Felt
Roofing cement, 10 oz tube	2	Roofing

Siding and trim

Item	Qty	Used for
5/8 in T1-11, 4×9 sheet	3	Front (high) wall
5/8 in T1-11, 4×8 sheet	3	Back (low) wall
5/8 in T1-11, 4×9 / 4×8 sheet	2 / 2	Sloped side walls
5/8 in T1-11, 4×8 sheet	2	Door leaves (one per leaf)
1/2 in plywood, 4×8 sheet	1	Eave soffit and header fillers
1×6 x 14 ft	2	Eave fascia
1×6 x 10 ft	2	Rake fascia
1×4 x 14 ft	6	Back corner trim, door casing sides, stiles, Z braces
1×4 x 12 ft	1	Door rails
1×4 x 10 ft	4	Front corner trim
1×4 x 8 ft	3	Door head casing, window casing
1×2 x 8 ft	2	Door stop and astragal
Drip cap, 10 ft	1	Over the door and window head casings
Insect screen, 2 ft x 25 ft	1 roll	Gaps at the eaves and soffit
Exterior paint and primer in one	4 gal	Two coats, about 448 sq ft each
Exterior caulk	3 tubes	Trim

Hardware and window

Item	Qty
Framing nails 3 1/2 in (16d), hot-dip galvanized	20 lb (about 696 nails + 10 %)
Siding nails 2 1/2 in (8d), hot-dip galvanized	10 lb
Sheathing nails 2 1/2 in (8d) for OSB	5 lb
Connector nails 1 1/2 in for ties and straps	2 lb
Construction adhesive, 10 oz tube	6
T-strap door hinges	6
Door handle and latch set	1
Barrel bolts for the fixed leaf	2
Exterior screws 1 1/4 in (door frame to T1-11)	1 lb
Exterior screws 2 1/2 in (hinge straps into framing)	1 box
Prefabricated window, 36 x 36 in rough opening	1
Flashing tape 4 in	1 roll
Wood shims	1 bundle

Cut list highlights

Most of the 8×12 lean-to cut list is square cuts: 10 front studs at 8′ 2 5/8″, 12 back studs at 6′ 3 1/2″, 10 floor joists at 7′ 9″, and skids, rims and long-wall plates at a full 12′ 0″. The parts below have angled cuts or many different lengths, so cut one, test it on your own frame, then cut the rest.

Part	Lumber	Cut length	Qty
Rafter (board length; about 9′ 7 1/2″ on the top edge)	2×4	9′ 8 3/8″	10
Fly rafter (rake)	2×4	9′ 8 3/8″	2
Side wall sloped top plate	2×4	7′ 7 3/4″	2
Side wall bottom plate	2×4	7′ 4 7/8″	2
Side wall studs	2×4	6′ 5 3/8″ to 8′ 3 1/4″	7 per wall, two of each length
Door header (2×8 doubled + 1/2 ply)	2×8	5′ 3″	2
Door trimmer	2×4	6′ 4 1/2″	2
Cripple over the door	2×4	1′ 2 7/8″	4
Window header (2×6 doubled + 1/2 ply)	2×6	3′ 3″	2
Window trimmer	2×4	5′ 10″	2
Blocking between rafters	2×4	1′ 1 3/4″ and 1′ 2 1/2″	4 and 14
Lookout block (rake overhang)	2×4	2 1/2″	12
Eave fascia	1×6	12′ 8″	2
Rake fascia (tip to tip; both ends plumb and parallel, 9′ 9″ along either edge)	1×6	9′ 10 3/8″	2
Corner trim, front side face (slope cut; short point 8′ 7 15/16″)	1×4	8′ 8 3/4″	2
Corner trim, back side face (slope cut; short point 6′ 8 1/2″)	1×4	6′ 9 3/8″	2
Door Z brace	1×4	3′ 2 3/16″	4

Rafters. The 9′ 8 3/8″ figure is the board each rafter needs, measured corner to corner. Along the top edge it is about 9′ 7 1/2″, including both 8 in overhangs. Plumb cuts are at about 14 degrees (3/12).

Each rafter gets two birdsmouths, one on each wall. The seat is 3 1/2 in and the notch cuts under 1 in into the 3 1/2 in deep 2×4, about a quarter of its depth. Cut one pattern rafter, test it on both walls, then trace the other 9. The 2 fly rafters sit on the lookout blocks and get no birdsmouth.

Side wall studs. Each side wall has 7 studs under a sloped top plate, and both walls use the same seven lengths: 6′ 5 3/8″, 6′ 8 1/4″, 7′ 0 1/4″, 7′ 4 1/4″, 7′ 8 1/4″, 8′ 0 1/4″ and 8′ 3 1/4″. Every length is the long point, from the top of the bottom plate to the underside of the sloped plate. These match the 8×10 lean-to, because the depth and wall heights are the same.

Cut two of each length and mark every stud with its wall and position as you go. Cut the top of each stud at the roof angle (3 on a speed square, about 14 degrees). The two tallest lengths are over 8 ft, so those four studs come from 10 ft boards.

Headers. The 60 in door gets a doubled 2×8 header with a 1/2 in plywood filler on 6′ 4 1/2″ trimmers, with four 1′ 2 7/8″ cripples above it. The back window header is a doubled 2×6 on 5′ 10″ trimmers, and it fills the space right up to the plates, so there are no cripples above it. Below the window go a 3′ 0″ sill and two 2′ 8 1/2″ cripples.

Plates. The front and back plates and cap plates run the full 12′ 0″, so they come straight off 12 ft boards. The side walls have a single sloped top plate, 7′ 7 3/4″, that runs between them, and the 4 twist straps tie the lean-to wall corners together.

Gable vs lean-to: what changes

We ran the same 8×12 footprint as a gable at 6/12, with 94 1/2 in walls and the ridge along the 12 ft side. The floor is identical; the walls, roof framing and siding all change. Our 8×12 shed material list covers the gable version in full.

Item	Lean-to (3/12)	Gable (6/12)
Rafters	10 2×4 at 9′ 8 3/8″ + 2 fly	20 2×4 at 5′ 3 1/2″ + 4 fly
Ridge board	None	2×6, cut 12′ 8″
Rafter ties and collar ties	None (no ridge, no outward thrust)	8 rafter ties + 4 collar ties
Wall studs	8′ 2 5/8″ front, 6′ 3 1/2″ back, stepped sides	7′ 6″ on all four walls
2×4 framing boards (plus 8 braces in both)	61	83
2×6 boards (not treated)	1	2
T1-11 sheets	12: five 4×9, seven 4×8	13, all 4×8
Roof OSB sheets	5	6
Shingle bundles	5	6
Felt	1 roll, laid double	1 roll, single
Drip edge, 10 ft	5	6
Framing nails	20 lb	27 lb
Extra hardware	4 twist straps	2 Z-flashing (wall to gable siding)
Floor (skids, joists, decking)	3, 10, 3 sheets	3, 10, 3 sheets

The lean-to saves 22 2x4s, a ridge board, one sheet each of OSB and T1-11, a shingle bundle, a drip edge piece and 7 lb of nails. In return, 5 of its 12 siding sheets are 4×9, which cost more and can be harder to find, and the felt goes on double. For the wider trade-offs, see lean-to shed pros and cons and our gable vs lean-to vs hip roof shed comparison.

Where the waste goes

These are the offcuts each stock length leaves on an 8×12 lean-to, and what to do with them:

• Rafters: 9′ 8 3/8″ from a 10 ft 2×4 leaves under 4 in, so a split or crowned end ruins the board. Buy one extra 2×4 x 10 ft as a spare rafter.
• Back studs: two 6′ 3 1/2″ studs come out of each 14 ft 2×4, leaving about 17 in. The two door trimmers pair up in one more 14 ft board.
• Front studs: 8′ 2 5/8″ from a 10 ft board leaves about 21 in each. Those 21 in pieces are your 8 brace stakes; point one end with the saw.
• Side studs: the five shorter lengths come from 8 ft boards and the two tallest from 10 ft boards, so the offcuts run from a few inches to about 2 ft. Keep the long ones as spare blocking in case a block splits.
• Floor joists: 7′ 9″ from an 8 ft board leaves 3 in for squaring the ends.
• Headers: the two 5′ 3″ door header pieces leave about 18 in of the 12 ft 2×8; the two 3′ 3″ window header pieces leave about 18 in of the 8 ft 2×6.
• Fascia: each 12′ 8″ eave fascia leaves about 16 in of a 14 ft 1×6. Each 9′ 10 3/8″ rake fascia leaves under 2 in of a 10 ft board, so there is no room for a bad end. If your 10 ft 1×6 stock has checked ends, buy 12 ft boards for the rakes instead.
• No spares: counts have no spares built in. Add 2 or 3 2×4 x 8 ft for warped or split boards, and one more 10 ft drip edge if your laps run long. The 4×9 T1-11 is often a special order, so order it early and consider one spare.

No board on this list is longer than 14 ft. A 14 ft board still hangs well past a pickup bed, so flag the overhang or ask the yard to deliver.

Tools you need

• Framing: circular saw, speed square, tape, chalk line, 4 ft level, framing hammer or nailer, drill driver and two sawhorses.
• Door cut-out: a jigsaw or reciprocating saw.
• Roof: an 8 ft stepladder for rafters and fascia, an extension ladder to get onto the roof, a hammer for the felt cap nails, tin snips for the drip edge and a utility knife for shingles.
• Pad and finish: shovel, rake, hand tamper, caulk gun and paint roller.
• Safety: glasses and hearing protection whenever you cut. Plan on one helper for most steps and two (three people in all) for raising the heavy 12 ft front wall.

Common mistakes

• Buying 4×8 siding for the front wall. The front wall is 103 1/8 in tall, over 8 ft, so the front and part of each side take 4×9 T1-11 sheets. Check that your yard stocks them before you order.
• Spacing the rafters at 24 in. The 2×4 rafters here were checked at 16 in on center, and the allowed span gets shorter at wider spacing, so keep 16 in or check your local permit office.
• Cutting side studs before the sloped plate is laid out. Both side walls step down from front to back, so lay out each sloped plate first, then cut and number the studs wall by wall.
• Single felt at 3/12. This list doubles the felt below 4/12. Read the minimum slope on the shingle wrapper, and check your local permit office for the underlayment rule in your area.
• Setting rafters crown down. Sight down each 10 ft 2×4 before you cut it and mark the crown (the high side of the bow). Every rafter goes crown up, or the roof shows dips you can see from the yard.
• Nailing the sloped plate on square-topped studs. Cut the 14 degree slope on the top of each side stud before the sloped plate goes on, or the plate rocks on the corners and the roof line wanders.
• Setting the low wall tight to a fence. All the roof water comes off the back edge, and you still need room to nail and paint the back siding. Leave a few feet of clear ground behind the shed.
• Letting roof water splash the back window. The window sits in the low wall, right under the drip edge. Lay a strip of gravel under the eave or hang a gutter so water does not splash back onto the sill and siding.
• Leaving the shed loose on its skids. A single-slope roof with 8 in overhangs catches wind. Ask your local permit office how sheds are anchored in your area before you set the skids.
• Untreated wood near the ground. Skids, rims and joists are pressure treated; plain framing lumber there rots. The USDA Wood Handbook explains why wet, untreated wood decays. Use hot-dip galvanized nails and treated-lumber rated screws in treated wood.

Setbacks, tie-downs and whether a 96 sq ft shed needs a permit vary by town, so check your local permit office before you order. For the build steps, see how to build a lean-to shed, and for the base under the skids, shed foundation options. For other sizes, try the shed material calculator, or compare the 8×10 lean-to material list and the bigger 10×12 lean-to material list.

Get the full plan

Our 8×12 lean-to plan is still in review, so it is not for sale yet. If you want a printed set with every step for the same 96 sq ft, the 8×12 gable shed plan is a 3DSHEDPLANS PDF with 3D drawings, cut details and its own printable material list, and the free 8×12 gable preview PDF shows the format.

For a single-slope roof today, the 8×16 lean-to shed plan has the same 8 ft depth, and the 6×10 lean-to shed plan is a smaller single-slope shed. Compare every size on the lean-to shed plans and shed plans pages.

Frequently asked questions

How much lumber do I need for an 8×12 lean-to shed?

For an 8×12 lean-to on skids with an 80 in back wall and a 3/12 roof, our generator lists 61 2×4 framing boards (12 of them 10 ft rafter stock), 12 pressure-treated 2x6s, 3 pressure-treated 4×4 skids, one 2×6 and one 2×8 for the headers, plus 8 2×4 x 12 ft braces you reuse later.

What is on an 8×12 shed material list besides lumber?

Sheets (3 floor plywood, 5 roof OSB, 12 T1-11, 1 soffit plywood), 5 shingle bundles, a roll of 15 lb felt, 5 drip edge pieces, 20 hurricane ties, 4 twist straps, about 20 lb of framing nails, 6 adhesive tubes, door hardware, a 36 x 36 in window and 4 gallons of paint.

How many sheets of plywood, OSB and T1-11 for an 8×12 lean-to shed?

3 sheets of 3/4 in tongue and groove plywood for the floor, 5 sheets of 7/16 in OSB for the roof, 12 sheets of 5/8 in T1-11 (five 4×9 and seven 4×8) and 1 sheet of 1/2 in plywood for the soffit and header fillers.

What size rafters does an 8×12 lean-to shed need?

The generator uses ten 2×4 rafters at 16 in on center, each cut from a 10 ft board to 9' 8 3/8". They span 89 in against a 98 in limit for SPF #2 at 30 psf ground snow. If you get more snow than that, or want 24 in spacing, check your local permit office.

Do you sell 8×12 shed plans with a material list?

Yes, as a gable. The 3DSHEDPLANS 8×12 gable shed plan PDF is $19.99 and has its own printable material list. Our 8×12 lean-to plan is still in review, so for a single-slope roof this page is the list for now.