For those of you that wonder what is the proper depth to dig footings for your deck columns and the best material to use, this blog by Archadeck of Charlotte will give you the answers!
Depending on where you live geographically, will help determine the answer. Up north where the frost line is deeper, it is common to have to dig your footers 3 – 4 ft deep and pour concrete. Down in the Charlotte, NC market it is only necessary to go 12 – 18″. It is common to use 2 – 16×16 cinder blocks stacked to provide a solid footing for the 6×6 columns to sit on. It is not necessary to add concrete on top of that unless you cannot find solid soil or the deck is unusually high off grade.
Finding solid soil can sometimes be a challenge. In rare cases we run across what is called “bull tallow” soil. This feels like quick sand in that you can take a prod and it will go straight through the soil. In this event, a soil engineer will be required to design a footing that will be structurally sound and safe for the deck to be built on. Deck building in Charlotte does have its own codes.
To gain more perspective and get hundred of deck and outdoor living photos, go to www.charlotte.archadeck.com