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An 8×20 shed material list for a gable shed on skids is 125 2x4s (116 for framing, 9 for temporary bracing), 21 treated 2x6s, 6 treated 4x4s, 5 sheets of 3/4 in plywood, 8 of OSB, 17 of T1-11 and 9 shingle bundles. It assumes 94 1/2 in walls, a 6/12 roof and 16 in spacing.

Every quantity and cut length on this page comes from the 3DSHEDPLANS plan generator, our software that models each board of the shed and counts what to buy. It checks spans, notches, splices and sheet coverage on every build, and this 8×20 build passed all 73 checks. The list is for one 60 in double door and one 36 x 36 in window. It is not the build in our 8×20 plan PDF (see below).

What this 8×20 shed material list assumes

The generator ran a shed 8 ft deep and 20 ft wide, with 160 sq ft of floor and the ridge running the 20 ft way. These are its settings:

  • Walls: 94 1/2 in tall including the bottom plate and double top plate, so wall studs are cut to 90 in (7′ 6″).
  • Spacing: studs, floor joists and rafters all at 16 in on center.
  • Roof: 6/12 pitch, 2×4 rafters, a 2×6 ridge board, 8 in eave overhang and 4 in rake overhang. The roof works out to about 213 sq ft.
  • Floor: three pressure-treated 4×4 skids 20 ft long, about 46 in apart (46.2 in), on a crushed stone pad 22 x 10 ft and 4 in deep (12 in past the shed on every side), with 2×6 joists cut to 7′ 9″ at 16 in on center and 3/4 in tongue and groove plywood.
  • Loads: the 2×4 rafters pass a span table check at 30 psf ground snow (SPF #2 at 16 in, 48 in run). That is the generator’s design assumption; if your area’s snow load may be higher, check your local permit office before you buy rafter stock.
  • Openings: a 60 in wide double door on 76 1/2 in trimmers in the 20 ft front wall, and one 36 x 36 in window in the 20 ft back wall. The two 8 ft gable walls have no openings.

Our 8×20 gable shed plan uses the same footprint but is a different build: a 108 in wide door in the long wall and an overall height of 148 3/4 in, so its header, roof framing, gables and shingle count all differ from this list. If you build the plan, shop from the plan’s own printable list.

What makes the 8×20 list different

An 8 ft depth is narrow, and that changes more than the board lengths. Compared with our 10×20 list, the generator’s 8×20 run shows:

  • Three skids, not four. At 46.2 in apart they stay under the generator’s 48 in limit.
  • No decking seam blocks. Two rows of 4×8 sheets cover the 8 ft depth, so the list buys no flat 2×4 blocks under the seams.
  • One sheet for both gables. Each gable triangle is only 8 ft wide with about 2 ft of rise.
  • No louvered gable vent. No gable stud bay is tall enough for one, so the siding stops short of the end rafters instead (see roof covering below).
  • 2×4 rafters even as a lean-to. The 89 in lean-to span passes the 2×4 check, where the 10×20 lean-to needs 2×6.

Shopping list by stage

A nominal 2×4 measures about 1 1/2 x 3 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.

Totals at a glance

Material Total
2×4 boards, all lengths (framing, braces, ridge post) 125
Pressure-treated 2×6 (17 joists, 4 for the two rims) 21
Pressure-treated 4×4 (one 8 ft and one 12 ft per 20 ft skid) 6
Pressure-treated 2×4 x 10 ft (skid splice scabs) 2
2×6 (ridge and window header) 3
2×8 (door header) 1
3/4 in T&G plywood sheets (floor) 5
7/16 in OSB sheets (roof) 8
5/8 in T1-11 sheets (walls, gables, door leaves) 17
1/2 in plywood sheets (soffit, header fillers) 2
3-tab shingle bundles 9

Floor

Item Qty Used for
Pressure-treated 4×4 x 8 ft, tagged for ground contact 3 One piece of each 20′ 0″ skid
Pressure-treated 4×4 x 12 ft, tagged for ground contact 3 The other piece of each skid
Pressure-treated 2×4 x 10 ft 2 Six 3′ 0″ splice scabs, one on each side of each skid joint
Pressure-treated 2×6 x 8 ft 17 Floor joists cut to 7′ 9″, including a second joist at the rim joint
Pressure-treated 2×6 x 10 ft and 12 ft 2 + 2 Two 20′ 0″ rim joists, cut 112 3/4 in and 127 1/4 in
3/4 in T&G plywood, 4×8 sheet 5 Floor decking (160 sq ft)
Crushed stone 3/4 in, loose 3.3 cu yd Gravel pad, measured loose before tamping
Deck screws 2 in (or 6d ring-shank nails), rated for treated lumber 4 lb Decking

Walls and roof framing

Item Qty Used for
2×4 x 8 ft 74 48 wall studs, cripples, window sill, short plate pieces, side cap plates, gable studs, lookout and frieze blocks
2×4 x 10 ft 14 14 rafter ties cut to 8′ 0″
2×4 x 12 ft 21 32 rafters and 4 fly rafters (two per board), back plate and cap plate pieces
2×4 x 14 ft 7 Front plate and cap plate pieces, door and window trimmers, collar ties
2×6 x 8 ft 1 Window header
2×6 x 10 ft and 12 ft 1 + 1 Ridge board (20′ 8″, spliced)
2×8 x 12 ft 1 Door header
Hurricane ties, H2.5A type or equal 32 Rafter to plate
Temporary braces 2×4 x 12 ft 8 Wall bracing, reused later
Temporary post 2×4 x 10 ft 1 Under the ridge joint until that rafter pair is set

The two header filler strips of 1/2 in plywood are ripped from a soffit sheet, so buy the soffit plywood with the wall lumber.

Roof covering

Item Qty Used for
7/16 in OSB, 4×8 sheet 8 Roof sheathing
15 lb felt, 400 sq ft roll 1 Underlayment
3-tab shingles, 26 per bundle 9 bundles Roof, starter course and ridge cap
Drip edge, 10 ft 7 Eaves and rakes
Roofing nails 1 1/4 in galvanized 7 lb Shingles
Roofing cap nails 1 in 2 lb Felt
Roofing cement, 10 oz tube 2 Roofing
Insect screen, 2 ft x 25 ft 1 roll The vent gaps under the end rafters and at the soffit

There is no louvered gable vent on this list. The generator found no gable stud bay tall enough for one, so it stops the gable siding 1 in under the end rafters and leaves that gap, screened, as the vent. The frieze blocks close the eave bays, so this is gable-only venting; if the shed will hold anything that minds damp air, plan extra vents before you close it in.

Siding and trim

Item Qty Used for
5/8 in T1-11, 4×8 sheet 14 Walls (448 sq ft, before the door and window cut-outs)
5/8 in T1-11, 4×8 sheet 1 Both gable triangles
5/8 in T1-11, 4×8 sheet 2 Door leaves (one per leaf)
1/2 in plywood, 4×8 sheet 2 Eave soffit and header fillers
Z-flashing, 10 ft 2 Wall siding to gable siding joint
Drip cap, 10 ft 1 Over the door and window head casings
1×6 x 10 ft and 12 ft 2 + 2 Eave fascia (two 20′ 8″ runs, spliced)
1×6 x 12 ft 2 Rake fascia (two 5′ 3 1/2″ pieces per board)
1×4 x 16 ft 2 Corner trim on the eave walls
1×4 x 14 ft 4 Door casing sides, door stiles, Z braces
1×4 x 12 ft 1 Door rails
1×4 x 8 ft 7 Gable-wall corner trim, door head casing, window casings
1×2 x 8 ft 2 Door stop and astragal
Exterior paint and primer in one 5 gal Two coats over about 629 sq ft
Exterior caulk 3 tubes Trim

Hardware and window

Item Qty
Framing nails 3 1/2 in (16d), hot-dip galvanized 37 lb
Siding nails 2 1/2 in (8d), hot-dip galvanized 14 lb
Sheathing nails 2 1/2 in (8d) for OSB 7 lb
Connector nails 1 1/2 in for the ties 3 lb
Construction adhesive, 10 oz tube 8
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 8×20 cut list is square cuts: 48 wall studs at 7′ 6″ and 17 floor joists at 7′ 9″. The table holds the parts that need angles, splices or a tape for each piece.

Part Lumber Cut length Qty
Rafter 2×4 5′ 3 1/2″ 32
Fly rafter (rake) 2×4 5′ 3 1/2″ 4
Ridge board (spliced) 2×6 20′ 8″ 1
Rafter tie (interior pairs, at the plates) 2×4 8′ 0″ 14
Collar tie 2×4 3′ 0 1/2″ 7
Lookout block (rake overhang) 2×4 2 1/2″ 16
Frieze block (over the eave walls, top beveled) 2×4 1′ 0 1/4″ to 1′ 1 3/4″ 30
Skid (spliced) PT 4×4 20′ 0″ 3
Rim joist (spliced) PT 2×6 20′ 0″ 2
Front and back wall plate (spliced) 2×4 20′ 0″ 4
Front and back cap plate (spliced) 2×4 19′ 5″ 2
Side wall plate 2×4 7′ 4 7/8″ 4
Side cap plate 2×4 8′ 0″ 2
Door header (2×8 doubled + 1/2 ply) 2×8 5′ 3″ 2
Door trimmer 2×4 6′ 4 1/2″ 2
Window header (2×6 doubled + 1/2 ply) 2×6 3′ 3″ 2
Window trimmer 2×4 6′ 1″ 2
Center gable stud (under the ridge) 2×4 1′ 8 3/4″ 2
Gable end studs 2×4 7 1/8″ and 1′ 3 1/8″ 4 each

Rafters. Each rafter needs a 5′ 3 1/2″ board with plumb cuts (26.6 degrees) at the ridge and the tail, which includes the 8 in eave overhang. The list buys 12 ft 2x4s and cuts two rafters from each, which leaves about 17 in per board. An 8 ft board holds only one rafter and wastes about 32 in, so you would need 36 boards instead of 18.

Mark the plumb cuts with a speed square pivoted to 6 on the common scale. The birdsmouth seat is 2 1/2 in, which makes the notch about 1 1/8 in deep, under the generator’s limit of one third of the rafter’s depth. Cut one pattern rafter, test it at both ends and the middle of the shed, then trace the other 31. The 4 fly rafters hang off the lookout blocks and the ridge extension, not a wall, so they get the plumb cuts but no birdsmouth.

Ridge. The ridge is 20′ 8″, not 20′ 0″, because it runs 4 in past each gable wall to carry the fly rafters. It is cut 112 in from a 10 ft 2×6 and 136 in from a 12 ft 2×6. The joint lands at a rafter pair so both ends of the splice are nailed through rafters; hold it on the temporary 2×4 post until that pair is set.

The 20 ft runs. The skids, rim joists, wall plates, cap plates, ridge and eave fascia are all longer than 16 ft, the longest board the generator will buy, so each is two boards with a planned joint. Each skid is one 8 ft and one 12 ft 4×4: the outer skids break at 8 ft and the middle skid at 12 ft, so neighboring joints are 4 ft apart, each under a floor joist and scabbed on both sides. Each rim breaks where a layout joist and a second joist sit side by side, so both rim ends nail into a full joist.

The splices come from the generator’s rule of no board over 16 ft, the longest length most home centers stock. If your yard sells 20 ft treated 4×4 and 2×6, one board per skid and rim removes those joints; recount the stock before you order. Spliced skids are not designed to be dragged, so if you may move the shed later, use single-length skids.

Wall plates. The front plates are cut 87 3/4 in and 152 1/4 in, with the joint centered on a full-height stud. The back plates use a full 8 ft and a full 12 ft board, joint on a stud. The 19′ 5″ cap plates also break on a stud, at least 4 ft from the plate joint below, so each layer laps the other’s joint. The side walls get 7′ 4 7/8″ plates, 1/8 in short of the gap so they drop in between the eave walls, and full 8 ft cap plates that lap the corners.

Headers. The 60 in door opening gets a doubled 2×8 header with a 1/2 in plywood filler, on trimmers cut to 6′ 4 1/2″, with four 6 1/4″ cripples above it. The bottom plate is cut out of the doorway after the wall is up, so the door leaves swing over the floor. The window gets a doubled 2×6 header on 6′ 1″ trimmers, two 11 1/2″ cripples above, a 3′ 0″ sill and two 2′ 11 1/2″ cripples below.

Gable studs. Each 8 ft gable has one 1′ 8 3/4″ center stud plus four end studs: two at 7 1/8″ and two at 1′ 3 1/8″, laid out 16 in on center from the corner so the T1-11 joints land on them. On an 8 ft wall that layout comes out even (16, 32, 64 and 80 in from the corner, center stud at 48 in), so both halves of each gable match. Still measure each stud off your actual end rafter before cutting, since a slightly long or short rafter changes them.

Gable vs lean-to: what changes

We ran the same 8×20 footprint as a lean-to (single-slope) roof at 3/12, with an 80 in low back wall, the door in the high front wall and the window in the back wall. The skids, joists and decking stay the same; the studs, rafters and siding change.

Item Gable (6/12) Lean-to (3/12)
Rafters 32 2×4 at 5′ 3 1/2″ + 4 fly 16 2×4 at 9′ 8 3/8″ + 2 fly
Ridge board 2×6, 20′ 8″ from a 10 ft and a 12 ft board None
Wall studs 7′ 6″ on all four walls 8′ 2 5/8″ front, 6′ 3 1/2″ back, stepped on the sides
2×4 framing boards bought 116 83
2×4 temporary braces and posts 9 8
2×6 boards bought (not treated) 3 1
T1-11 sheets 17, all 4×8 16: seven 4×9, nine 4×8
Roof OSB sheets 8 8
Shingle bundles 9 8
Felt 1 roll 2 rolls, laid double below 4/12
Soffit plywood 2 sheets 1 sheet
Extra hardware 2 Z-flashing 4 twist straps at the wall corners
Framing nails (16d) 37 lb 26 lb
Floor 3 skids, 17 joists, 5 sheets 3 skids, 17 joists, 5 sheets

On an 8 ft deep shed the lean-to rafters stay 2×4: the generator checks an 89 in span against a 98 in limit for 2×4 at 30 psf. On our 10×20 shed material list the deeper lean-to needs 2×6 rafters, so the narrow footprint is what keeps 2×4 rafters here. Each side wall has 7 studs stepping from 6′ 5 3/8″ to 8′ 3 1/4″ under a 7′ 7 3/4″ sloped top plate.

Each lean-to rafter is 9′ 8 3/8″ from a 10 ft board, which leaves under 4 in, so check the board ends before you mark it. The high front wall and the tall end of each side wall take 4×9 siding sheets, which some yards have to order. At 3/12, read the minimum slope on the shingle wrapper and follow the maker’s low-slope instructions. For single-slope layouts, see the 8×16 lean-to shed plan, all lean-to shed plans and our gable vs lean-to vs hip roof comparison.

Where the waste goes

  • Wall studs: 90 in from a 96 in board leaves about 6 in each.
  • Rafters: two 5′ 3 1/2″ rafters from a 12 ft board leave about 17 in. Cut lookout blocks or short gable studs from those ends if you want, but the list already buys boards for them.
  • Floor joists: 7′ 9″ from an 8 ft board leaves 3 in for squaring the ends.
  • Rafter ties: the fourteen 8′ 0″ ties come from 10 ft boards, leaving about 2 ft each. Cut the 8 brace stakes from these offcuts; at just under 24 in after the saw kerf, they are close enough for stakes.
  • Splice scabs: three 3′ 0″ scabs per 10 ft treated 2×4 leave about 12 in.
  • 20 ft runs: the skids and back plates use full boards with factory ends and no offcut. The rim pieces leave about 7 in and 17 in, the front plate pieces about 8 in and 16 in, and the ridge pieces about 8 in each.
  • Side cap plates: each uses a full 8 ft board with no trim room, so check that the factory ends are square at the yard.
  • Floor decking and wall siding: 5 floor sheets give exactly 160 sq ft for a 160 sq ft floor, and 14 wall sheets give 448 sq ft for 448 sq ft of wall. Neither count has a spare, so many builders buy one extra sheet of each. Tongue and groove sheets often cover a little under 48 in once the joint closes, so two rows can end up to about 1 in short of the back rim; check the net width on your sheets and dry-fit before gluing.
  • No spares: the counts include nothing for rejects. Pick straight stock at the yard, and add a few 2×4 x 8 ft if you expect to cull warped or split boards.

The longest pieces bought are 16 ft: the two corner trim boards for the eave walls, each cut into two 7′ 11 1/8″ pieces. Four 1×4 x 8 ft boards work too if their factory ends are square, since that leaves only 7/8 in each. Everything else is 8, 10, 12 or 14 ft stock.

Tools for an 8×20 build

  • Circular saw, speed square and framing square for 48 stud cuts and 36 rafters; cut the 2 1/2 in lookout blocks from a long clamped stick with a stop block, never as loose scraps
  • Framing hammer or framing nailer for about 1,340 16d nails plus 10 percent, and a drill/driver for the decking and hinge screws
  • 4 ft level, 25 ft tape for checking that the floor diagonals match, and a string line for the 20 ft rims and plates
  • A rented plate compactor for 3.3 cu yd of gravel, laid in thin layers
  • A crew: the generator plans for a helper on most steps and 5 people to raise the 20 ft back wall
  • Safety glasses and hearing protection for the saw and nailer, and gloves and a dust mask when cutting the treated lumber

Common mistakes

  • Mixing up 8×20 and 20×8. In this list the ridge runs along the 20 ft side and the door sits in a 20 ft wall. If the ridge runs the 8 ft way, the roof spans 20 ft and each rafter’s run grows from about 48 in to about 120 in, so the rafter size, ridge and gables all have to be worked out again.
  • Lining up the splices. Every 20 ft member here is two boards. If the skid, rim, plate and cap plate joints all fall at the same spot, the floor and walls get a hinge line. Keep them where the list puts them.
  • Closing the gable vent gap. With no louvered vent, the 1 in screened gap under each end rafter is the gable ventilation. Do not run the gable siding up tight to the rafters or caulk the gap shut.
  • Forgetting the door sheets. The siding cut out of the doorway is 76 1/2 in tall, shorter than the 77 1/4 in door leaf, so each leaf needs its own new T1-11 sheet.
  • Skipping rafter ties. A ridge board is not a beam. The 14 rafter ties at the plates stop the 20 ft walls from spreading. The 7 collar ties, on every other interior pair, hold the rafter pairs together near the ridge; they do not replace the rafter ties.
  • Swapping materials without recounting. This list is for 3-tab shingles and T1-11. Architectural shingles, metal roofing or lap siding cover differently, so recount from the coverage printed on the bundle or the maker’s install guide.
  • Untreated wood near the ground. Skids, rims and joists are pressure treated, with ground-contact rated skids; the joists and rims sit only a few inches above the gravel, so ask your yard whether its treated 2x6s are rated for ground contact too. Use hot-dip galvanized nails and treated-lumber rated screws in treated wood. The USDA Wood Handbook covers why wet, untreated wood decays.

Whether a 160 sq ft shed needs a permit, and what setbacks and tie-downs apply, varies by town, so check your local permit office before you order. Our shed permit checklist lists what to ask. Ground anchors or tie-downs are not counted in this list, so ask the same office what your area expects for a 160 sq ft shed on skids.

For how to read any list like this one, see our shed material list guide. For other sizes, try the shed material calculator. For the base under the skids, see shed foundation options, and for a rough budget, see how much it costs to build a shed.

Get the full plan

The 8×20 gable shed plan is a 3DSHEDPLANS PDF with 40+ steps, 3D images and its own printable material list for its 108 in door layout. For the nearest sizes, see the 8×14 gable shed plan, the 10×20 gable shed plan and the 8×16 lean-to shed plan, or compare the 8×12 shed material list and the 10×20 shed material list.

Want to see the format first? Download the free 8×20 gable shed plan preview PDF. Need more or less room? Compare all gable shed plans or browse every size on the shed plans page.

Frequently asked questions

What is on an 8×20 shed material list?

For an 8×20 gable shed with 94 1/2 in walls and a 6/12 roof, our generator lists 125 2x4s, 21 treated 2x6s, 6 treated 4x4s, 5 sheets of 3/4 in plywood, 8 of OSB, 17 of T1-11, 2 of 1/2 in plywood and 9 shingle bundles, plus trim, nails and hardware.

How many 2x4s do I need for an 8×20 shed?

125 in all for an 8×20 gable shed with a 60 in double door and one window. That is 116 framing boards (74 at 8 ft, 14 at 10 ft, 21 at 12 ft, 7 at 14 ft), 8 temporary wall braces and 1 temporary ridge post.

How many sheets of plywood, OSB and T1-11 does an 8×20 shed need?

5 sheets of 3/4 in tongue and groove plywood for the floor, 8 sheets of 7/16 in OSB for the roof, 17 sheets of 5/8 in T1-11 (14 for the walls, 1 for both gables, 2 for the door leaves) and 2 sheets of 1/2 in plywood for the soffit and header fillers.

What changes if I build an 8×20 lean-to shed instead?

On the same floor, a 3/12 lean-to uses 83 framing 2x4s instead of 116, no ridge board, 16 T1-11 sheets (seven of them 4×9), 8 OSB sheets, 8 shingle bundles and 2 rolls of felt. Its 2×4 rafters still pass the generator's span check on the 8 ft depth.

Are there free 8×20 shed plans with a materials list?

This page is a free 8×20 materials list with cut lengths. The 3DSHEDPLANS 8×20 gable shed plan PDF adds 40+ steps, 3D images and its own printable list, and a free 8×20 preview PDF shows the format before you buy.

Shed building guides