If you're planning a new deck in Cedar Rapids for next spring, the winter months are a good time to learn what goes under it. Footings are where a deck meets the ground, and the American Wood Council's prescriptive deck guide (DCA 6, based on the 2015 International Residential Code) sets out clear rules for them. [AWC DCA 6]
Footing basics from DCA 6
All footings must bear on undisturbed soil at least 12 inches below the ground surface or below the frost line, whichever is deeper. [AWC DCA 6]
Your local building department, the "authority having jurisdiction," sets the frost line, so ask them for it. [AWC DCA 6]
Bearing conditions are to be verified in the field by the building official before concrete is placed. [AWC DCA 6]
Deck footings closer than 5 feet to an exterior house foundation wall must bear at the same elevation as the house footing. [AWC DCA 6]
Don't build footings over septic systems, leach fields, utility lines or enclosed meters, and call 811 to have utilities marked before digging. [AWC DCA 6]
Pre-manufactured post anchors must be galvanized or stainless steel. [AWC DCA 6]
Other things to plan for
Decks more than 30 inches above grade need a guard, and openings in guards must not let a 4-inch sphere pass through. [AWC DCA 6]
A deck ledger is not to be attached to brick veneer. [AWC DCA 6]
All construction and materials must be approved by the authority having jurisdiction, so check local permit rules early. [AWC DCA 6]
CEDAR RAPIDS