How to Build a Shed From Scratch (Complete Step-by-Step Guide)

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Building a shed from scratch is a weekend project — but only if you go in with a real plan. This guide walks you through every stage: foundation, floor, walls, roof, and weatherproofing. We’ll use a 10×12 gable shed as the working example. It’s the most common beginner size: big enough for a mower, bikes, and garden tools; small enough to build solo.

Finished size: 10′ wide × 12′ deep × 8′ tall at the walls (10’+ at the roof peak)
Skill level: Intermediate beginner — you need to be comfortable with a circular saw and know how to use a speed square
Build time: 2–3 full weekends
Estimated cost: $1,200–$1,800 depending on siding and roofing choices

Before You Start: Permits and Site Rules

In most Australian councils and US counties, sheds under a certain size don’t require a permit — but check your local council/HOA rules first. In Australia, sheds up to 10m² (roughly 10×10 ft) are typically exempt but this varies by state and by setback from boundaries. In the US, most municipalities allow sheds up to 120 sq ft without a permit.

Never assume you’re exempt. A shed built without the required approval can be ordered demolished. A 15-minute phone call to your council saves thousands.

Watch the Full Build

And a second complete build showing the framing in detail:

Materials List — 10×12 Gable Shed

Foundation & Floor

Wall Framing

Roof Framing

Roofing

Siding & Trim

Door & Hardware

• Pre-hung exterior door (32″×80″ is standard) OR build a Z-brace door from 1×6 boards
• Door hardware: hinges (3 per door), hasp latch or deadbolt
• Joist hanger hardware: 16 joist hangers + 1¼” joist hanger nails
• Structural screws: 3″ (GRK or similar) — 5 lbs
• Roofing nails: 2 lbs
• Exterior caulk: 4 tubes
• Exterior primer + paint: 2 gallons

Tools Required

• Circular saw with framing blade
• Framing square (essential for rafter layout)
• Speed square
• Drill/driver + impact driver
• Chalk line
• Level (4′ level minimum, 6′ preferred)
• Tape measure
• Hammer
• Ladder (6′ and 8′)
• Pneumatic nail gun (optional — speeds up sheathing and framing significantly)

Step-by-Step Build

Stage 1 — Site Preparation and Foundation

Site selection: Choose a level spot with good drainage. Avoid low spots where water pools. Allow at least 18″ clearance from any fence or boundary (more if your council requires it).

1. Mark out a 10’×12′ area with stakes and string lines
2. Remove any grass or topsoil within the area — you want the floor sitting on gravel, not soil that will compact unevenly and hold moisture
3. Dig 6 holes for your concrete deck blocks, 12″ diameter × 6″ deep, at the four corners and two midpoints on the long sides
4. Fill each hole with compactable gravel, tamp firmly
5. Set a deck block in each hole. Use a long straight board and a level to confirm all 6 blocks are on the same plane. This is the most important step in the whole build — an unlevel foundation makes every subsequent step harder

Checking level across all blocks: Set your 4′ level on a long straight 2×4 spanning between blocks. Adjust blocks by adding or removing gravel underneath until all 6 are within ¼” of each other in height.

Stage 2 — Floor Frame

1. Lay your two 4×6 skid beams across the deck blocks running the 12′ length. These are your main runners
2. Build the floor frame on top: set 2×6 rim joists along all 4 perimeter edges, joined at corners with 3″ screws
3. Add 2×6 floor joists between the long rim joists on 16″ centres (you’ll have 7 interior joists across the 10′ width)
4. Attach each joist with joist hangers — don’t just toenail them, hangers carry the load
5. Check the frame is square: measure diagonally corner to corner. Both diagonals should match within ¼”
6. Nail down ¾” T&G plywood panels for the floor. Stagger the seams. Apply construction adhesive to every joist before laying each sheet

Stage 3 — Wall Framing

Frame all four walls flat on the floor, then tilt them up. This is far easier than framing in place.

Wall anatomy: Each wall has a bottom plate, two top plates (double top plate), and studs on 16″ centres.

1. Front wall (with door): Frame a 10′ wall with a rough door opening 2″ wider and 2″ taller than your door (so 34″×82″ for a 32″×80″ door). Add a doubled 2×6 header above the opening
2. Back wall: A simple 10′ wall with studs every 16″
3. Side walls: 12′ long. The top plate follows the roof pitch — mark the top edge of your end studs at the correct height for the rafter line. For an 8′ wall height at the eaves with a 4/12 pitch roof, the end studs are 8′ but the centre stud (at the peak) is taller
4. Tip all walls up into position, brace temporarily with 2×4 diagonal braces screwed to stakes in the ground
5. Nail the bottom plates to the floor using 3″ structural screws or 16d nails every 16″
6. Connect wall corners and check that all walls are plumb (perfectly vertical). Adjust braces until a level confirms plumb, then lock the braces in
7. Install the double top plate, lapping the corners for structural connection

Stage 4 — Roof Framing

Roof framing is where most first-timers slow down. The key is the rafter template.

Rafter calculation for a 4/12 pitch (4″ rise for every 12″ of run): For a 10′ wide shed, the run is 5′ (half the width).

• Rise = 5′ × 4/12 = 20″ (1’8″)
• Rafter length (the hypotenuse) = √(60² + 20²) = √(3600 + 400) = √4000 = 63.2″ ≈ 63¼”
• Add 12″ for eave overhang = total rafter board length ≈ 76″

1. Cut one rafter to the calculated length with a plumb cut at the ridge (vertical cut at the peak, angled to match pitch) and a bird’s mouth notch where it sits on the wall top plate
2. Bird’s mouth: This is a notch cut into the underside of the rafter so it sits flat on the wall plate. For a 4/12 pitch: the seat cut is level (horizontal) and 3½” wide; the plumb cut is angled to match the pitch
3. Test this template rafter on the wall before cutting all 14 — lay it in place and check that the bird’s mouth seats flat, the plumb cut aligns with the ridge centreline, and the tail hangs out at the correct overhang
4. Once confirmed, use the template to trace and cut all remaining rafters
5. Set the ridge board first, supported temporarily at the correct height, then attach rafters in pairs on opposite sides
6. Nail each rafter pair at the ridge with 3 × 16d nails, and toe-nail the bird’s mouth into the top plate

Stage 5 — Roof Sheathing

1. Start at the bottom edge (eave) of one side. Snap a chalk line to keep the first course straight
2. Nail ½” OSB or plywood sheets with 8d ring-shank nails every 6″ along edges and 12″ in the field
3. Stagger seams. Don’t let four corners meet at the same point
4. Install metal drip edge along the eaves (before felt) and along the rakes/gables (after felt)
5. Roll out 15# roofing felt horizontally from the bottom, lapping each course 6″ over the one below. Staple every 12″

Stage 6 — Shingles

1. Install a starter strip of shingles along the eave edge (adhesive side up — it seals the first full course)
2. Lay the first course of shingles flush with the drip edge
3. Each subsequent course overlaps the one below so the tab slots don’t align (stagger by 6″ each course)
4. Nail each shingle with 4 nails above the adhesive strip — if nails miss this zone, shingles blow off in wind
5. Cap the ridge with ridge cap shingles or cut full shingles into thirds and fold them over the peak

Stage 7 — Siding and Trim

1. Install corner boards (1×4) on all four corners before the siding — siding butts up against these
2. T1-11 siding goes on in 4’×8′ panels, starting from a bottom corner. Leave a 2″ gap between the bottom edge of the siding and the ground to prevent rot
3. Nail every 6″ along edges and 12″ in the field with 8d galvanised nails
4. Caulk all seams, around the door frame, and where siding meets corner boards
5. Prime and paint within 2 weeks of installation — unprimed T1-11 will swell and delaminate

Stage 8 — Door

The simplest approach for a shed is a Z-brace door: two panels of 1×6 boards running horizontally, held together by a diagonal 1×6 brace (the Z) and vertical 1×4 battens on the back. This is stronger than it looks and costs about $40.

• Cut 6 horizontal boards per door half to fill the opening width
• Glue and screw 1×4 battens across the back to hold them together
• Add the diagonal Z-brace (runs from the bottom hinge corner up to the opposite top corner) to prevent sagging
• Hang on three 4″ strap hinges per leaf, shimming the door into the frame with even gaps (⅛” all around) before fastening hinges

Common Mistakes That Cause Big Problems

• Skipping the level foundation check — if the blocks aren’t level, nothing will be square or plumb above them. Fix it before you nail a single board
• Not using pressure-treated lumber for the floor frame — regular lumber sitting close to ground will rot within 3–5 years. All floor framing must be PT
• Framing studs on 24″ centres to save lumber — for T1-11 siding (which is also structural), 16″ centres are required. T1-11 on 24″ centres will flex and crack
• Forgetting bird’s mouth depth — if the seat cut is too deep, you weaken the rafter. The rule: the seat cut should not exceed ⅓ of the rafter depth
• Not caulking siding seams immediately — water infiltrates horizontal seams fast. Caulk the day you install siding

Cost Breakdown

A similar shed from a kit costs $1,500–$3,500, and a contractor-built shed runs $3,000–$7,000 for this size. Building yourself saves $1,500–$5,000 and gives you a better result because you control every material choice.

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