Measure the area you would like your shed to fit on. It is important to make the concrete base the exact size the finished shed structure will be. If the base is larger, rain will splash up and soak the bottom boards causing them to rot.
Dig out the area the new shed will be placed. The concrete base is going to be half under ground and half above. Most concrete bases are 75 mm (3 inches) to 100 mm (4 inches). Use the larger if the ground is soft. Leave an additional 2 inches for the gravel or ground-up brick. The example is based on a 6-by-8 foot shed base that is 4 inches deep.
Use a stamper to level the ground to a smooth surface. Use 2-by-6 boards to frame out the area for the concrete. Use wooden pegs to frame up the corners to 90 degrees and use nails at a diagonal angle to secure it in place. Lay broken brick or gravel down.
Mix the concrete according to manufacturer's directions. Mixing can be done in an old wheelbarrow or large container. Spread the concrete mix into the frame for the base.
Use a flat wooden float to spread the mix to a smooth surface. Tap the sides of the framework with a hammer to help make a straight edge and get out air bubbles. Make sure it is level and evenly spread. Allow to dry according to manufacturer's directions. This normally takes several days to dry with a plastic cover sheet and spraying with water so it will dry slowly.
Coat all the wood pieces that will be used to construct the shed with 3 coats of preservative. This will keep the wood from rotting in the weather elements. Follow manufacturer directions. Wear safety glasses and gloves.
Set the 4-by-4 wood posts onto the concrete slab, spaced 12 inches apart. Place a piece of plywood board on top of these posts and nail every couple of inches down the board to connect the two. Place an underlayment piece to protect the board from moisture.
Construct the walls individually away from the shed. After constructed, they will be attached to the base. Lay 2-by-4 wood pieces cut to the size of the height and width of the walls. Insert a 2 by 4 in the middle as a support beam.
Check to make sure the corners are square at 90 degrees, then nail them together to keep in place. Set additional 1-by-4 boards vertically lined up across the frame. Plywood could also be used if desired. Nail the boards onto the frame going through the 1 by 4 into the 2 by 4 for the frame. Repeat this for each wall; remember to cut the boards if any openings, such as windows, are wanted. Make sure one wall has an opening for the door.
Have a helper assist you to place the wall onto the base. Use a 2-by-4 board and connect it 2 feet up the side of the wall and 2 feet down the base for support while you nail in the bottom frame to the base. See above picture for reference. Repeat for each wall until all four walls are up and nailed onto the base.
Use additional nails to go through the middle and upper edges of the frame for additional support. Place a 2-by-4 beam across the top to build the roof. Use nails and L-bracket steel supports to connect the beam to the walls.
Place plywood boards on top of the wall's frame to create the roof. Attach the plywood by nailing into the framing boards of the walls.
Cut four 2-by-4 pieces with a 45 degree on one end for them to meet up. Take one set of 2 and place them under the roof onto of the wall and nail into place. This will add additional support and block out the elements.
Use a caulking sealant to seal all corners, edges and roof lines. If any windows were installed, caulk sealant around those as well.
Attach the door to the wall frame leaving 1 mm of space around the edges to allow for expansion. Use hinges to connect it to the frame. Install a lock onto the front.
Choose type of roofing and exterior material wanted. Metal, shingle or vinyl can be used. Install material over framing of shed according to manufacturer's instructions. This will provide additional protection against the outside elements.
Add any additional shelves, cabinets or storage as needed inside the shed.
Things You Will Need
- 4 2-by-6 wood pieces
- 24 bags of concrete mix (80 lbs. each)
- 16 bags of gravel (50 lbs. each)
- Wheelbarrow or buckets
- 6 4-by-4 wood posts
- 25 2-by-4 wood pieces
- 100 1-by-4 wood pieces
- 4 soft wood stakes
- 3 6-by-8 foot plywood boards
- Nail gun (optional)
- Windows (optional)
- Preservative for wood
- 3 hinges and one lock for door
- 2 L-brackets for roof
- Use safety glasses with all power tools. Materials may be increased for a larger shed or decreased for a smaller shed.