How to Figure Out Deck Footing
- 1). Visit the local building department to determine the building requirements for deck footings in your area. Review the depth and spacing requirements to meet the code requirements, which is specified based on the frost line in your area. Colder areas have a deeper frost line. For example, in Minnesota the frost line is 42 inches, while warmer states may experience little if any frost.
- 2). Review the code requirements to determine the specific size and shape required for the footings. Use these requirements to plan how you will design the footings. Determine if you are required to use a tube form per the local building code, which helps form the footer to a specific size and shape.
- 3). Decide how deep to dig the holes for the footers so they meet code requirements. The code often specifies that you need a base material 6 inches or more below the footer itself. Choose the base material to fill the bottom of the hole underneath the footer, which is typically compacted gravel to allow for drainage.
- 4). Calculate the number of footings needed based on your deck design. You'll need a footing for each post on the deck. Mark out the deck area as dictated by the building plans. You'll need a footing at each of the corners on the side away from the house, as well as footings in between for the rest of the posts, which should be evenly spaced along the side.
- 5). Draw a sketch that shows each of the footings, along with the spacing between each. Include an underground view of the footings to show the depth and size of the hole, as well as the depth of the gravel at the bottom.
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