Building a tool shed can seem like a daunting task, but it may turn out to be one of the easiest projects you choose to do. You can finish the whole project in a single day. The following steps will show you how to build a 12x12-foot outdoor tool shed.
Step 1 - Building Permits
Even though the structure will be on your personal property, you may still need a permit. Call your local city permit office and tell them the size of shed you're constructing. If you need a permit, either get one or adjust your plan to to fit within the local guidelines that don't require a permit or license.
Step 2 - Foundation and Frame for the Shed
There are no shortcuts to creating a sturdy frame. It has to be strong and large enough to support not just the shed but everything you will place inside of it.
Stake out and string off a 12x12-foot wide area using your tape measure. This will be where the base and frame of the shed will be built.
Put the shovel to use and excavate the area inside the stakes to a depth of one foot. Use the tamper and compress the ground inside the excavated area to make it flat as well as sturdy.
Fill the excavated area with six inches worth of class V gravel, then tamp it down so that it becomes embedded into the ground.
Lay 4 of the 12-foot long pieces of wood around the perimeter of the excavated area and nail them together where they join at the corners. Place 4 pieces of 12-foot long pieces of wood in the center of the excavated area, evenly spaced out at three feet, and running vertically. Use the mallet to knock them in place.
Use the saw and cut the last of the 12-foot long pieces into four 3-foot long sections. Pound them in place with the mallet between the vertical pieces. These pieces of wood don't have to be lined up evenly.
Fill the gaps in the inner frame with class V gravel. Make sure they are even and level then tamp them down.
Step 3 - Building the Base for the Shed
With the foundation in place you can now add the base of the shed. The base is the floor of the shed with some differences like it stretching over the entire perimeter of the foundation, it's thicker than a normal flooring, and the wall will nail directly into it.
Put one of the pieces of ¾-inch thick plywood on top of the frame. Center the plywood on the frame then screw it in place using the 8-inch long wood screws every 6 inches. Repeat with the remaining piece of plywood.