If you need any building permits, obtain them before you start building your shed. If you don’t get a permit, you might have to tear down the entire shed and start over, even if you follow the other local building codes. You could also be fined, depending on local laws.
You may prefer to build your shed on a concrete slab to protect it from water that might seep up from the ground. If so, level the ground and lay your concrete slab before you start building the base of the shed.
Attach a rim joist along the outer edge of each outermost support beam; each of these will need to be the same length as the beam underneath. Install a series of floor joists across the entire length of the support beams; these will need to be the same length as the distance between the two rim joints so that they’ll fit between them. In the example design, the floor joists are all separated by 14. 5-inch (35. 6 cm) gaps except for the outermost two, which are 13 3⁄4 inches (34. 9 cm) from their immediate neighbors; this is to allow a standard piece of plywood to line up with the outermost edge of the outermost joist but only cover half of an interior joist, allowing its neighbor to cover the other half so that both can be supported properly. [2] X Research source Install a piece of blocking between each pair of floor joists along the center support beam. These will keep the floor joists from moving. [3] X Research source
Your shed floor may also be screwed down with 3-inch (7. 6 cm) deck screws.
Build the framework for the back wall. Make the top and bottom beams (a. k. a. the plates) the same length as the length of the floor. To keep your measurements simple, make the spacing between the vertical studs identical to the spacing between your floor joists. Note that the back wall should be lower than the front wall so that the roof slopes and directs rain away from the door. [5] X Research source Build the framework for the front wall. The front wall should be the same as the back wall except taller and with a door frame so that you can hang a door in the shed when you’re done. [6] X Research source Build the frameworks for the side walls. The bottom plate of each side wall should be the same length as the distance between the bottom plates of the front and back wall (so that the side walls will fit between them). The standard spacing between vertical wall studs in the US is 16 inches (40. 6 cm) (from center to center, not from edge to edge); since this stud spacing doesn’t perfectly divide into the total length of the side walls in the example design, the two outermost studs make up for this discrepancy by being slightly closer to their neighbors. Most importantly, the top plate is angled so that the roof will be sloped, which makes the height of each vertical stud slightly different. If you’re not sure how to calculate the necessary height of each vertical stud in advance, make the two outermost vertical studs first, lay them the correct distance apart, cut a top plate that spans this distance, and then cut each remaining vertical stud individually based on the distance between the top and bottom plates at that exact location. [7] X Research source Assemble the four wall structures. If possible, nail the wall structures to the underlying support from the bottom up. However, if this is not possible with the design you’ve chosen, simply nail them downwards through the plywood and joists or toenail them into place by driving the nails downwards and at an angle. You may need other people to help you hold the wall structures up until they can be attached. [8] X Research source
