There is a simple way to test moisture levels in your soil. Scoop an empty coffee can into the soil, leaving three inches of space at the top of the can. Fill up the rest of the can with water. Wait until the water soaks into the soil, and repeat. Time how fast it takes the water to soak in. Anything slower than 1 inch per hour means you have very low moisture levels. [2] X Research source Instead of using home methods of measuring, sometimes it is best to call in a professional. They will be able to provide all of the diagnostics tests which will tell you everything you need to know about the soil you plan to use. They will even be able to measure the flatness of your soil, and whether or not you need to adjust your foundation’s height.
The dimensions of the perimeter hole should be at least 2 feet wide by 2 feet deep, preferably 3 feet deep. [8] X Research source Remember that you are not digging the entire area for your planned building. You are just digging the perimeter of the building. The area where your building will be is formed in later steps. After you are done carving out the area to lay the foundation, use a shovel to clear out any excess dirt and debris that might still be laying there.
Set your rebar in first. Then add the grade pins on top of the rebar. Set each grade pin about 2 feet apart from one another, and a foot away from the corners. Then lift up the rebar and attach it to the grade pins. There should be a manual hook on the grade pins to attach the rebar. Do not use a tie or string, which can cause damage to the footing. Make sure that the rebar is equidistant from the base of your opening, as it is from the sides.
Make sure to use the correct mixture of concrete. If there is not enough water, or too much mix, the concrete will not dry correctly[10] X Research source How to Make Concrete
You can add in a little dirt on the outer part of the outside boards to help them stand firm and upright. Use metal bars outside of the wooden frames in order to hold the boards tightly together. You can also cut boards or plywood strips 6 to 8 inches wide and 2 to 3 feet long and use duplex nails to span across the joints of your foundation boards to hold them together. Be sure all of your staking is sturdy or you risk “blowing out” the boards and losing all of the concrete. Use plenty of stakes to prevent this from happening.
This is important because if you do not insert the pins, your walls can shift, causing the building to collapse. Pour the second and third walls coming off of the initial wall. The concrete will form over the pin and join the walls together. Reinsert pins into the sides of the second and third walls.
If you are using gravel to fill up the foundation and pour a slab on top, then the gravel should be 6 to 8 inches deep. You will also need to use a plate compactor in different directions until the gravel is well compacted. Next, add another 6 to 8 inches of gravel (called lifts) and repeat the compaction until the gravel is 4 to 6 inches from the top of the wall for the slab depth.
You can also add in bar chairs which will prop up the wire mesh. These bars are inserted directly into the plastic sheeting. You will need one every two to three inches.
