How To Build A Shed
If your looking for something to compliment your garden, a place to pot your plants, or just somewhere to keep the lawn mower then building your own garden shed is great idea. The choices for shed design and function vary widely and can range from very expensive to extremely inexpensive, but for the price, nothing beats building a shed by hand, and with a little bit of planning, a weekend of good weather, and a few friends, a solid shed can be built that will last for years to come.
When planning your shed, keep in mind the dimensions of the materials you will be working with. Plywood comes in eight by four foot sections and 2x4 lumber can also be obtained in eight foot sections, so an eight by eight foot square shed with eight foot walls will require almost no cutting of plywood or the stud lumber, and a twelve by twelve foot floor plan will require only cutting one floor board in half.
After planning your shed its time to move on to the real work and find out how to build a shed that is not going to fall over after a few months, so first of all assemble the supplies according to your plans. Floor joists should be 2x8 pressure treated lumber, and should be spaced no more than eight inches apart, wall studs should be 2x4 lumber (non pressure treated is fine) and spaced 16 inches OC, on center meaning from the center of one stud to the center of the next.. Rafters should be 24 inches apart and made of 2x6 lumber. Anywhere horizontal lumber must bear a load, such as the top of the wall sections, above a door, or above a window, and additional 2x4 should be planned. Remember that two 2x4s nailed and glued together handle stress better than a single 4x4 piece of lumber, and will be less expensive as well.
The plywood used should be 3/4th of an inch thick for the floor, ½ inch thick for the roof and simple paneling for the walls, and if you plan to “finish” the interior, as in have walls and not bare studs, then double the amount of plywood for the walls. The roof will also need roofing paper and shingles (33 square feet of roof space per bundle, plan accordingly and buy a bundle or two extra because it is almost impossible to match color of shingles when replacing one later.)
If you plan to have power or water in your shed, then electrical supplies and plumbing supplies will be needed, including a breaker box inside the shed, at least two outlets per wall (there can never be enough outlets) with the first being a GFCI box, junction boxes, lighting of your choice and a switch for the lights. We would also suggest an outdoor plate cover for an outlet outside the shed. Consult a local plumber for the best position for a spigot and consult an electrician to wire the shed to the main.
Preparation
Start by preparing the ground under the shed and placing concrete foundation blocks at the corners of the shed and spaced at four foot intervals, making sure the top of the foundations are all level. Frame the floor joists by nailing the four outside pieces together in a square then nail the remaining joists to the outside frame. Have your friends help place the floor frame onto the blocks and square the floor by measuring corner to corner.
Using a string or rope, assure the two diagonals are equal before proceeding further with the shed. If this critical step is omitted then nothing else on the shed will be square and nothing will seem to fit quite right, leading to a shed that looks shoddy and is shoddy.
The Floor And Walls
Once the foundation is square the floor plywood should be nailed in place. Starting in a corner, nail the board to one side of the frame then recheck the square before nailing the board to the other side of the corner. Once one of the plywood boards is nailed in place, the floor should remain square. When the floor is finished, start on the walls.
Frame them the same way the floor was framed; just make sure the studs are spaced sixteen inches, also, any doors or windows should be accounted for, just make sure that windows have at least one stud below the window, and add an extra 2x4 above the window or door frame prior to finishing the studs. When the walls are finished, raise them up and plumb them (vertically level). Brace the walls temporarily with scrap lumber until all the walls and the roof is finished. As each wall is plumbed, nail to the floor frame through the floor boards.
Now For The Roof
By now the shed should like an unfinished box and the trickiest part begins, making the roof. The length of your rafters depends on the pitch of the roof, as does the number of boards of plywood, but for a climate with mild weather, a shallow pitched room will suffice. Build two beam supports, the length of which will determine the pitch of the roof with three pieces of 2x4 scrap lumber each with the two outer 2x4s one inch longer than the middle one.
Nail these to the center of the front and back walls, plumb them and nail the center beam, a 2x8 extending one foot longer than the wall on either side; this overhang is necessary to minimize rain on the walls. Starting at the front of the shed, measure 24 inches from the end of the beam and mark the placement for the first rafter. Have someone raise a rafter up and rest it on the wall with the lower edge against the beam. Mark a plumb line from the upper edge down for your cut line. Mark that angle with a T-bevel and use if for both ends of all your rafters. Cut the rafters so they extend a foot beyond the walls.
After cutting the rafter, nail it to the beam, and proceed with all the other rafters except for the ones on the ends, rafters not supported by the walls. If the rafters were cut correctly, the overhang ends should but cut at an angle so there is a vertical face, and on to this nail a 1x4 fascia board, cut the same length as the beam, on either side, then attach the final rafters on the ends of the roof.
Next, attach the wall paneling and then the roof plywood and the shed is almost finished. Put a layer of roofing tar paper on the roof and then shingle the roof starting on the lowest edge, and the first layer of shingles should be laid backwards (with the gaps pointing toward the roof) and overhanging the roof slightly, followed by a layer on top of that one pointing the correct way. Alternate the layers of shingles so that no gaps overlap and allow water to seep into the roof. At the crest of the roof, attach an aluminum roof vent and then cover the remaining crest with cut shingles. Cover any exposed nails with roofing tar.
And Finally...With all that done you can frame the door and windows, following the instructions that came with the doors and windows and attach these finished products to your shed. Paint the shed and furnish the interior as per your tastes and enjoy.
A well built shed will match the home, will withstand the weather, and will resist termites and other insect infestations. It also will be the envy of the neighborhood, and only you will know that you spent a fraction of what your neighbor spent for the rickety store bought thing that he has never quite gotten level.
