With spring in the air we are excited to be working on exterior home projects. This month we are all about siding, patios, and of course, decks! With decks on the brain, we wanted to take a moment to discuss the importance of footings. Footings act to spread the load of the deck from the surface of a support over a larger surface of soil, allowing the ground to adequately support it. In this way, footings ensure that the deck doesn’t sink into the ground under the load weight. Footings are particularly important here in Minnesota as they can also serve to protect the deck from moving when the soil freezes in the winter.
The number of footings that your deck will require is dependant on the size of both your deck beams and the footings themselves. The larger the beam and footing size, the fewer footings that will be required. However, as a general rule of thumb, both footings and posts should be less than 8′ apart. Decks with multiple angles or those built to sustain hot tubs, porches, or other loads, will require additional footings per foot. Be sure to discuss your intended deck usage with your contractor to determine the best fit for you!
When excavating for your footings it is important to make sure that they reach below the frost level – or the depth at which the soil is expected to freeze – and are placed at least 12 inches below unsettled soil. Typically in Minnesota the frost level reaches approximately 48 inches. However, your local building inspector will be able to tell you the required depth for your specific geographic area. Speaking of inspectors, remember that your footings will need to pass inspection as well. When checked, they will be measured to ensure that the holes’ base and depth sizes meet the specifications of your project’s pre-approved plans. In addition, the footing holes must be free of both loose dirt and water.