Take all the stuff you plan to put in your shed outdoors and place it together to give you an idea of the size shed you'll need. Measure around the perimeter of these things with a measuring tape, and draw your shed plans with these dimensions.
Purchase posts, 2-by-4 floor joists and plywood decking that have been pressure-treated. Pressure-treated wood will not rot when exposed to moisture that may come from wet tools or weather conditions.
Pace off the dimensions of your garage. Use the rubber mallet to hammer a stake into the ground at the center of your corner post location. Then place the carpenter's triangle in this location. Use the chalk line to and the measuring tape to mark the location of the walls. Take care to keep the walls in line with the carpenter's triangle. Place stakes at the corners for all posts, and halfway down each line for center posts.
Dig post holes that are 1/3 the height that your shed will be from ground to the roof line (a shed with a 6-foot roof line will have posts sunk 2 feet into the ground). Fill these holes with 2 inches of gravel, and then place the posts in your post holes. Use 2-by-4 boards to brace the supports, and make sure they are perfectly upright with the carpenter's level. Mix concrete in a wheelbarrow and fill the holes. Allow the concrete to cure before proceeding.
Nail 2-by-4 boards around the perimeter of the support posts at the floor level to form the exterior floor joists. Use joist hangers to attach 2-by-4 boards every 3 feet across the inside width of the building to the exterior floor joists.
Nail the plywood sheets over the exterior floor joists to form the flooring of your shed.
Cut your posts to the correct height at the roof line. Nail the four roof beam boards to the exterior perimeter of the posts. Use a carpenter's level to ensure that the beams are straight.
Attach wall joists to the three exterior walls every 3 feet. Measure the garage door, and space wall joists at this distance on the exterior wall where the garage door will hang. If there is room between these garage door joists and the wall, place joists in this space.
Attach your noggins horizontally across the outside of your walls, spacing them every 2 feet. For the wall holding the garage door, measure and cut the noggins to fit the walls around the garage door. The noggins are there to give you something to attach your exterior walls to.
Raise trusses to the beams and nail them in place. Nail plywood sheeting to walls and roof. Attach garage door to roof beam and wall joists.
Hang siding on the plywood exterior. Attach roofing tin to the plywood roof using roofing nails, ensuring that the tin overlaps. Caulk along the seams of tin to prevent leaks. Cap the roof's ridge with tin roofing caps.
Things You Will Need
- Measuring tape
- 6 4-inch-by-4-inch pressure treated posts
- Post hole digger
- Chalk line
- Carpenter's level
- Rubber mallet
- Carpenter's triangle
- 11 pressure-treated 2-by-4 boards
- 14 joist hangers
- 43 sheets of pressure treated 4-foot-by-8-foot plywood (floors, walls and roof)
- 37 2-by-4 boards (wall joists, roof beams and noggins)
- 9 trusses
- Circular saw
- Garage door
- Tin roofing supplies
- Roofing nails
- For the purposes of this article, all equipment quantities are for a 24-foot-by-24-foot' building. For smaller sheds, use fewer materials.