Everything visible about a deck sits on something nobody looks at again after the first week.
Why clay matters
Georgia red clay expands when wet and contracts when dry, and it does that every year. A footing set too shallow rides that movement, which is why some decks develop a slight bounce or a corner that sits low.
Depth
Below the frost line, which around Woodstock means a minimum of twelve inches and often more. Ask any contractor for the number — someone who has not thought about it will not have one ready.
Slope changes the size, not just the length
On a sloping lot the posts on the downhill side carry more weight and have less soil holding them laterally. They need larger footings, not simply longer posts — and that is a common shortcut.
What a bouncy deck usually means
Either joist spacing that was set too wide, or footings that have moved. The first is a design decision made at build time; the second is a foundation problem. Neither is fixed by replacing boards.
Drainage
Water pooling around a post base is what starts the rot that ends a deck. Where the ground holds water we grade it away before setting anything, because concrete does not fix drainage.
Deck construction covers how we build. Finished decks are on our Facebook page.
