DIY Trench Footers

Dig the Trench

• 1

  Measure out the area to dig for the trench using a 100-foot tape measure. You must complete this step to locate the exact position for each of the stakes, which will include one on each corner of the footer.

• 2

  Tie a string to one of the stakes, then run the string around the perimeter of the stakes to outline the footer. The string should sit just a few inches from the ground.

• 3

  Mark the line for the footer on the ground with marking spray paint to provide the guide line for the excavator. Remove the stakes and string.

• 4

  Dig the footing using a backhoe excavator to the necessary depth as required by your local zoning laws. Using the excavator rather than a pick and shovel allows you not only to work much more quickly but also to obtain the correct width for the footer trench without unnecessary shaping of the trench. The best width for the trench is 2 feet.

• 5

  Pack down the soil thoroughly in the bottom of the trench using a soil compactor. Have the site inspected by your local zoning inspector if necessary.

Pour the Footer

• 6

  Add limestone gravel to the bottom of the trench to the necessary depth as required by your local zoning laws. The depth of the gravel usually ranges from 3 to 6 inches. Use a rake to spread the gravel evenly around the bottom of the trench.

• 7

  Place board forms into the footer trench so they lie parallel to one another. Imagine that you are creating an aboveground moat with the boards. You'll pour concrete for the footer in liquid form into this wooden form. The zoning commission will have given you exact necessary dimensions you should use for construction of these forms based on the approved plans for your building. Follow these requirements precisely to avoid run-ins with the zoning inspector, who will need to inspect the footer once you have poured it.

• 8

  Pour the concrete for the footer into the form, smoothing the top with a mason's trowel. If you are using concrete anchor bolts, press them into the wet concrete at an interval of one every 2 feet and smooth out the concrete against the bolts to provide a watertight seal. Allow the footer to cure for at least two days prior to removing the forms.

• 9

  Remove the forms from the footer after the concrete has cured, then fill the rest of the trench with the dirt you originally excavated from it. This step is called "back filling," and it concludes the construction of the trench footer.