Free shed plan
12x20 Shed Plans: Gable Roof
A garage-style shed with room for a riding mower and a full workbench. The long sides are spliced from 16 ft boards, and at 240 sq ft you should check your permit rules first.
- 240
- 165
- 38
- 6.2%
Specifications
| Footprint | 12' wide x 20' deep (240 sq ft) |
|---|---|
| Roof | Gable, 6/12 pitch, 6" eaves |
| Wall height | 7' 4-3/4" to top of plates |
| Overall height | about 11' 9-3/8" from grade to peak |
| Framing | 2x4 walls at 16" OC, 2x6 rafters at 16" OC, 2x6 joists at 16" OC |
| Foundation | 4 pressure-treated 4x6 skids on a gravel pad |
| Door | double door, 48" x 78" on the front wall (rough opening) |
| Windows | 2 x 24" x 24" rough opening |
| Longest board | 16 ft, longer members spliced over supports |
| Design snow load | 30 psf |
Notes on this design
Where the long members are spliced
- Left side wall: plates spliced over a stud at 105-3/4", cap plate at 160" from the left end.
- Right side wall: plates spliced over a stud at 105-3/4", cap plate at 160" from the left end.
- Ridge board: joint centered on a rafter pair at 112" from the front.
- Skids: butt joints at 112", 160" from the front, staggered from skid to skid, each with a 4 ft 2x6 splice plate on both faces.
- Rim joists: joint centered on a joist at 112" from the front; double that joist.
- Fascia: butt joints centered on a rafter tail at 112", with a 3/16" gap, sealed, and two nails each side of the joint.
Foundation and floor
4 pressure-treated 4x6 skids run front to back on a compacted gravel pad. The floor joists run across them, so no joist spans more than 46-13/16". See the foundation guide for leveling and squaring.
Wall framing
Walls are drawn from the outside. The side walls run the full depth and carry the rafters; the front and back gable walls fit between them. The wall framing guide walks through layout and raising.
Front wall: layout marks
| Studs, left edge | 0", 11-3/4", 27-3/4", 41-1/2", 43", 92-1/2", 94", 107-3/4", 123-3/4", 135-1/2" |
|---|---|
| Door rough opening | 44-1/2" to 92-1/2" from the left end (48" wide) |
| Door header | 2-2x6, bottom at 78", top at 83-1/2" above the subfloor |
Back wall: layout marks
| Studs, left edge | 0", 11-3/4", 27-3/4", 43-3/4", 59-3/4", 75-3/4", 91-3/4", 107-3/4", 123-3/4", 135-1/2" |
|---|
Left side wall: layout marks
| Studs, left edge | 0", 1-1/2", 15-1/4", 31-1/4", 47-1/4", 63-1/4", 79-1/4", 95-1/4", 105", 106-1/2", 132", 133-1/2", 143-1/4", 159-1/4", 175-1/4", 191-1/4", 207-1/4", 223-1/4", 237", 238-1/2" |
|---|---|
| Window rough opening | 108" to 132" from the left end (24" wide) |
| Window sill | top of the rough sill at 54" above the subfloor |
| Window header | 2-2x6, bottom at 78", top at 83-1/2" above the subfloor |
Right side wall: layout marks
| Studs, left edge | 0", 1-1/2", 15-1/4", 31-1/4", 47-1/4", 63-1/4", 79-1/4", 95-1/4", 105", 106-1/2", 132", 133-1/2", 143-1/4", 159-1/4", 175-1/4", 191-1/4", 207-1/4", 223-1/4", 237", 238-1/2" |
|---|---|
| Window rough opening | 108" to 132" from the left end (24" wide) |
| Window sill | top of the rough sill at 54" above the subfloor |
| Window header | 2-2x6, bottom at 78", top at 83-1/2" above the subfloor |
Roof framing
32 2x6 rafters at 16" on center, 6/12 pitch with a 6" eave. A 2x8 ridge board and a 2x4 rafter tie at every pair keep the walls from spreading. The rafter guide shows how to lay out the pattern.
Span checks
| Member | Size | Span | Allowed | Result |
|---|---|---|---|---|
| Rafters | 2x6 | 5' 11-1/4" | 11' 11-1/8" | OK, 101% spare |
| Floor joists | 2x6 | 3' 10-13/16" | 8' 7-13/16" | OK, 122% spare |
| Window header, left side wall | 2-2x6 | 2' 3" | 7' 1-1/2" | OK, 217% spare |
| Window header, right side wall | 2-2x6 | 2' 3" | 7' 1-1/2" | OK, 217% spare |
Shopping list
| Lumber to buy | Qty |
|---|---|
| 4x6 pressure-treated (ground contact) | |
| 8 ft | 2 |
| 10 ft | 2 |
| 12 ft | 2 |
| 16 ft | 2 |
| 2x6 pressure-treated (ground contact) | |
| 10 ft | 2 |
| 12 ft | 11 |
| 16 ft | 8 |
| 2x4 framing lumber | |
| 8 ft | 47 |
| 12 ft | 25 |
| 16 ft | 14 |
| 2x6 framing lumber | |
| 8 ft | 28 |
| 12 ft | 4 |
| 2x8 framing lumber | |
| 10 ft | 1 |
| 12 ft | 1 |
| 1x4 exterior trim board | |
| 8 ft | 12 |
| 1x6 exterior trim board | |
| 12 ft | 4 |
| Sheets, roofing and hardware | Buy |
|---|---|
| Sheet goods | |
| 3/4" tongue-and-groove plywood subfloor, 4x8 | 8 sheets |
| Panel siding (T1-11 or engineered wood), 4x8 | 16 sheets |
| Panel siding for the gable ends, 4x8 | 2 sheets |
| 7/16" OSB roof sheathing, 4x8 | 12 sheets |
| Z-flashing for the horizontal siding joints, 10 ft pieces | 3 pieces |
| Roofing | |
| Asphalt shingles, 3 bundles per square | 10 bundles |
| Starter strip shingles | 1 bundle |
| Hip and ridge cap shingles | 1 bundle |
| Synthetic roof underlayment, 10-square roll | 1 roll |
| Drip edge, 10 ft pieces | 8 pieces |
| Fasteners and hardware | |
| Framing nails, 16d common, 3-1/2" x 0.162" | 20 lb |
| Toenail nails, 10d box, 3" x 0.128" | 9 lb |
| Galvanized siding nails, 2-1/2" (8d) | 15 lb |
| Roof sheathing nails, 2-1/2" (8d) | 9 lb |
| Exterior screws for the subfloor, 2" | 4 lb |
| Rafter-to-plate connectors (hurricane ties) | 32 |
| Roofing nails, 1-1/4" | 8 lb |
| Exterior screws for splice plates, 3" | 1 box |
| Construction adhesive (subfloor) | 4 tubes |
| Shed ground anchors | 4 |
Lumber-yard takeoff
The whole shopping list on one printed page, with a box to tick for each line at the yard.
12x20 Gable Shed plan: lumber-yard takeoff
12' x 20' gable, 6/12 roof. Tick each line as it goes on the cart. theshedplanner.com
Lumber
- 24x6 pressure-treated (ground contact), 8 ft
- 24x6 pressure-treated (ground contact), 10 ft
- 24x6 pressure-treated (ground contact), 12 ft
- 24x6 pressure-treated (ground contact), 16 ft
- 22x6 pressure-treated (ground contact), 10 ft
- 112x6 pressure-treated (ground contact), 12 ft
- 82x6 pressure-treated (ground contact), 16 ft
- 472x4 framing lumber, 8 ft
- 252x4 framing lumber, 12 ft
- 142x4 framing lumber, 16 ft
- 282x6 framing lumber, 8 ft
- 42x6 framing lumber, 12 ft
- 12x8 framing lumber, 10 ft
- 12x8 framing lumber, 12 ft
- 121x4 exterior trim board, 8 ft
- 41x6 exterior trim board, 12 ft
Sheet goods
- 8 sheets3/4" tongue-and-groove plywood subfloor, 4x8
- 16 sheetsPanel siding (T1-11 or engineered wood), 4x8
- 2 sheetsPanel siding for the gable ends, 4x8
- 12 sheets7/16" OSB roof sheathing, 4x8
- 3 piecesZ-flashing for the horizontal siding joints, 10 ft pieces
Roofing
- 10 bundlesAsphalt shingles, 3 bundles per square
- 1 bundleStarter strip shingles
- 1 bundleHip and ridge cap shingles
- 1 rollSynthetic roof underlayment, 10-square roll
- 8 piecesDrip edge, 10 ft pieces
Fasteners and hardware
- 20 lbFraming nails, 16d common, 3-1/2" x 0.162"
- 9 lbToenail nails, 10d box, 3" x 0.128"
- 15 lbGalvanized siding nails, 2-1/2" (8d)
- 9 lbRoof sheathing nails, 2-1/2" (8d)
- 4 lbExterior screws for the subfloor, 2"
- 32Rafter-to-plate connectors (hurricane ties)
- 8 lbRoofing nails, 1-1/4"
- 1 boxExterior screws for splice plates, 3"
- 4 tubesConstruction adhesive (subfloor)
- 4Shed ground anchors
Foundation
- 1 rollLandscape fabric, enough to cover 14' x 22'
Site prep
- 3.8 cu ydGravel base: compactable crushed stone, 4" pad 1 ft wider than the shed on every side, before compaction
Cut list
| Qty | Size | Length | Piece |
|---|---|---|---|
| Front wall | |||
| 2 | 2x4 | 76-1/2" | Jack stud, door |
| 2 | 2x6 | 51" | Header ply, door (48" opening) |
| 2 | 2x4 | 2-1/4" | Cripple above door header |
| 8 | 2x4 | 84-1/4" | Stud |
| 2 | 2x4 | 137" | Bottom and top plate |
| 1 | 2x4 | 144" | Cap plate (second top plate) |
| 2 | 2x4 | 6-5/8" | Gable stud (long point) |
| 2 | 2x4 | 14-5/8" | Gable stud (long point) |
| 2 | 2x4 | 22-5/8" | Gable stud (long point) |
| 2 | 2x4 | 30-5/8" | Gable stud (long point) |
| Back wall | |||
| 10 | 2x4 | 84-1/4" | Stud |
| 2 | 2x4 | 137" | Bottom and top plate |
| 1 | 2x4 | 144" | Cap plate (second top plate) |
| 2 | 2x4 | 6-5/8" | Gable stud (long point) |
| 2 | 2x4 | 14-5/8" | Gable stud (long point) |
| 2 | 2x4 | 22-5/8" | Gable stud (long point) |
| 2 | 2x4 | 30-5/8" | Gable stud (long point) |
| Left side wall | |||
| 2 | 2x4 | 76-1/2" | Jack stud, window |
| 2 | 2x6 | 27" | Header ply, window (24" opening) |
| 2 | 2x4 | 2-1/4" | Cripple above window header |
| 1 | 2x4 | 24" | Rough sill, window |
| 2 | 2x4 | 51" | Cripple below window sill |
| 18 | 2x4 | 84-1/4" | Stud |
| 2 | 2x4 | 105-3/4" | Bottom and top plate |
| 2 | 2x4 | 134-1/4" | Bottom and top plate |
| 1 | 2x4 | 156-1/2" | Cap plate (second top plate) |
| 1 | 2x4 | 76-1/2" | Cap plate (second top plate) |
| Right side wall | |||
| 2 | 2x4 | 76-1/2" | Jack stud, window |
| 2 | 2x6 | 27" | Header ply, window (24" opening) |
| 2 | 2x4 | 2-1/4" | Cripple above window header |
| 1 | 2x4 | 24" | Rough sill, window |
| 2 | 2x4 | 51" | Cripple below window sill |
| 18 | 2x4 | 84-1/4" | Stud |
| 2 | 2x4 | 105-3/4" | Bottom and top plate |
| 2 | 2x4 | 134-1/4" | Bottom and top plate |
| 1 | 2x4 | 156-1/2" | Cap plate (second top plate) |
| 1 | 2x4 | 76-1/2" | Cap plate (second top plate) |
| Roof | |||
| 32 | 2x6 | 89-1/8" | Common rafter |
| 1 | 2x8 | 112" | Ridge board |
| 1 | 2x8 | 128" | Ridge board |
| 16 | 2x4 | 144" | Rafter tie (ends cut to roof slope) |
| Floor | |||
| 2 | 4x6 PT | 112" | Skid (runs front to back) |
| 2 | 4x6 PT | 128" | Skid (runs front to back) |
| 8 | 2x6 PT | 48" | Skid splice plate (one each side of a joint) |
| 2 | 4x6 PT | 160" | Skid (runs front to back) |
| 2 | 4x6 PT | 80" | Skid (runs front to back) |
| 16 | 2x6 PT | 141" | Floor joist |
| 2 | 2x6 PT | 112" | Rim joist (sides) |
| 2 | 2x6 PT | 128" | Rim joist (sides) |
| 1 | 2x6 PT | 141" | Doubled joist at a rim joint |
| Trim | |||
| 8 | 1x4 | 96" | Corner trim board |
| 2 | 1x6 | 112" | Fascia board (eaves) |
| 2 | 1x6 | 128" | Fascia board (eaves) |
| 4 | 1x4 | 87-3/16" | Rake trim board |
Build it in 7 steps
- 1
Check permits and pick the site
Confirm what your building department and zoning rules require for a 240 sq ft shed, then call 811 before you dig. Read the guide
- 2
Build the foundation
Level a gravel pad 1 ft wider than the shed and set 4 pressure-treated 4x6 skids 46-13/16" on center. Read the guide
- 3
Frame the floor
Two 20' rim joists and 16 joists at 141", 16" on center, squared by the diagonals and covered with 3/4" tongue-and-groove plywood.
- 4
Frame and raise the walls
Build each wall flat with 84-1/4" studs, headers over the openings and a double top plate. Raise, plumb and brace. Read the guide
- 5
Cut and set the rafters
Make one pattern 2x6 rafter, 86-3/8" plumb cut to plumb cut, test it, then cut 31 more. Set the 2x8 ridge and add a 2x4 rafter tie at every pair. Read the guide
- 6
Sheathe and roof
Nail 12 sheets of 7/16" OSB, add drip edge and underlayment, then shingles.
- 7
Side and trim
Hang the panel siding, then the corner boards, fascia and rake trim. Fit the doors and windows and seal every cut edge.