How to Pour a Simple Concrete Footer
It’s hard to think about spring, but believe me it’s just around the corner. You may have ambitious plans to build that long-awaited DIY room addition this year. Good for you! Many a homeowner just like you has successfully completed a small simple room addition.
All structures need a great foundation so they can stand the test of time. Foundation walls almost always are supported by a footer. The footer is the lowest structural item that’s found in most houses. Its purpose is to spread out the weight of the structure onto the soil. A footer is just a concrete beam that’s poured in direct contact with the soil. The foundation wall rests on this footer.
You can access a handy quick start guide for concrete footers with more tips and a full tool list here: Concrete Footer Quick Start Guide
Degree of Difficulty:
Step One: Check with your local building department concerning building permits, and the frost depth in your area. The bottom of the footer needs to be below the frost depth. It’s always a great idea to go just a little deeper than recommended.
Step Two: Be sure you locate and identify any underground utilities before you dig. Call 811 and have all utilities marked so you don’t get hurt or cause neighbors to have problems if you slice into a buried electric, water or gas line.
Step Three: You can dig by hand, I’ve done it for many a footer, but tool rental businesses now rent very small excavators that can fit in a small yard. You don’t need a full-size backhoe to dig a shallow footer.
Step Four: Footers need long pieces of reinforcing steel. One-half-inch diameter, #4, is almost always sufficient. This steel needs to be continuous through the entire footer and be held up at least 3 inches from the soil. Overlap splices at least 16 inches.
Step Five: The footer should be at least 8 inches thick. Most architects call for a footer to be 20 inches wide, but I always poured mine 24 inches wide.
Step Six: You can just pour the concrete in a 24-inch wide trench if you like. It’s key the concrete is very level. Drive vertical pieces of reinforcing steel into the soil every 4 feet in the center of the footer as leveling reference points. Use a laser level or builder’s transit to get the tops of these pins at the same height.
Step Seven: Have plenty of help on hand when the concrete truck arrives. Be sure to have spare wheelbarrows in case one breaks. Don’t overfill wheelbarrows as concrete is very heavy. Consider renting a small machine with a bucket that you can use to make trips from the concrete truck to the footer.
Step Eight: Wear rubber boots if you’re working in the trench to level the concrete. Concrete will cause burns to skin, so wash off any as soon as possible. Use a simple wood float or magnesium float to smooth the concrete.
Summary: No one task, other than digging the hole and wheelbarrowing the concrete, is really hard in this job. It’s all a matter of common sense and thinking the job through. Be sure you double check the footer is square before you dig. Layout the foundation on the ground before digging. When the diagonal measurements are the same in a square or rectangular foundation, it’s square!