Deck Footing Depth Chart

For example the size of the deck plus whether it has a roof will change the depth of the footing.

Deck footing depth chart. Decks and other permanent structures require deck supports and footings made from structural strength concrete mix. Also the soil type will alter the width of the deck footing. For example if you are building a 10x10 deck attached to a house with two footings on the corners you could calculate the loads for the footings in the following way. First draw a line dividing the deck into two halves between the house and the footings.

Fill with gravel for drainage. When you contact your local building department to get your building permit ask what the frost depth requirement is and the required size and shape of the footings. Pour about six inches of gravel into the hole for drainage. Only if desired or required by code.

Ensure a solid footing. In frigid minnesota the frost depth is 42 in whereas a warmer state like missouri may have a frost depth of only 1 ft. A comparison of the footing sizes i calculated for the example deck resting on 1500 psf soil in the sizing deck footings article and dca 6 table b3 shows an almost identical result. My calculations came up with 15 3 4 in.

Make the hole slightly wider than the footing frames. If you live in a warm climate like south florida where frost rarely ever occurs you may be allowed to place your footings on grade but in very cold regions like minnesota and canada you will need to dig down 48 or more. Make them at least six inches past the frost line or to your local building code. The depth you are required to set your frost footings will vary from region to region across the country.

Lay out landscape paper. Tamp it down with a 4 4 post. Going one step further use a pre formed bell shaped footing to adapt to a variety of form dimension diameters. Deck plans are approved on the assumption that the deck will be used only as a deck for the life of the structure.

It is important to check local building codes for construction requirements in your area. It s also important that the footings for a building or a deck be well below the frost line so the posts don t shift as the ground freezes and thaws. It takes a lot of time and effort to lay down a square 2x4 footing frame in order to make the footing seen above. Because footing sizes setbacks structural supports and a host of other deck components are different for enclosed porches than for decks.

It s important to know the frost line depth for construction purposes. It is important that you indicate on you plans the desire to convert the deck at a future date. Water pipes should always be set below a frost line to prevent them from freezing in the winter. Diameter center footing size and table b3 calls for a 16 in.