Excavating and Forming Concrete Foundations
The first and most crucial structural component of any house or large building is its foundation. According to HomeTime.com, excavating and forming a concrete foundation can take a short amount of time, perhaps a week, and the steps are straightforward. However, you must ensure that each is step is performed correctly and professionally; otherwise, the structural integrity of your home may be at risk. Does this Spark an idea?
Other People Are Reading
-
Preparation
-
If you applied for a bank loan to cover the costs of excavating and forming a concrete foundation, HomeTime.com advises that you wait for the bank to approve your loan before beginning any work, including preparatory surveying. Once you have approval, stake out the corners of where your house -- or other structure -- will be on the property. Avoid areas that are swampy, marshy or otherwise unstable, as these conditions can make installing a concrete foundation more difficult. Once you have staked out where the foundation will go, clear away all debris, rocks, trees and other physical obstructions.
Tools
-
After preparing the construction surface, start digging the hole where your concrete foundation will rest. For small structures, traditional tools like backhoes and shovels can do the job, but for larger structures, you will need a front-end loader, which is a tractor outfitted with a large, scoop-like attachment for digging. To hold the concrete in place while it cures, assemble concrete forms using a power saw and nail gun or screw gun. When the hole is dug and the forms are set, pour in the concrete and spread it around using shovels, concrete rakes, hand trowels and bull floats. A bull float, which is similar to an over-sized squeegee, consists of a long handle with a large, flat rectangular surface at its end. To eliminate air bubbles and voids from a curing concrete foundation, use a mechanical concrete vibrator.
-
Materials
-
To construct the concrete forms for the foundation, use scrap wood or inexpensive plywood, as you will remove the forms once the concrete cures. RafterTales recommends using 2-by-10-inch boards. Before pouring the concrete, cover the bottom surface of the excavation site with a layer of gravel or sand, which will help prevent moisture from penetrating the foundation's surface. You may also want to install a vapor barrier on top of this layer, which is a highly water-resistant membrane. For the concrete, Building Foundation Tips recommends using a 2,500 psi mix for smaller structures and a 4,500 psi mix for larger structures. Psi, or pounds per square inch, is a measurement of pressure and indicates how strong concrete will be once it cures.
Tips
-
To prevent rain from putting a damper on your excavation plans, dig a large hole, or sump, at the center of the site and use it to collect water for easy pumping. To ensure that the walls of the foundation form perfect right angles with each other, Ask the Builder recommends measuring to 3 feet along one wall and to 4 feet on an adjacent wall and then connecting the two points on the floor with a line. If the corner forms a 90-degree angle, the line you create will be exactly 5 feet.
-
