Deck builds are permitted structural projects. This article covers the sequence and the elements. A deck permit is not optional — the inspection process catches the problems that cause deck collapses.
01Ground-level deck — basic build sequence
A ground-level deck (within 30 inches of grade) requires footings, posts, beams, joists, and decking. Footings are concrete pads or piers below frost line. Posts sit on post bases anchored to the footings. Beams span between posts. Joists span between the ledger (attached to the house) and the outer beam. Decking runs across the joists. The permit submittal includes a plan showing footing locations, framing sizes, and connection hardware.
02Ledger attachment
The ledger connects the deck to the house and carries half the deck load. The house rim joist behind the siding is the attachment point. Lag bolts or structural screws in an alternating pattern, sized and spaced per the span table for the load, connect the ledger to the rim joist. The ledger is flashed to direct water away from the house wall — metal flashing behind the siding and over the ledger is not optional.
03Concrete patio pour
A concrete patio is 4 inches thick over 4 inches of compacted gravel base. Excavate and compact the subgrade, set forms at finished grade elevation, add gravel and compact again. Pour concrete and screed level with the forms. Float and broom-finish the surface. Install control joints at 8–10-foot intervals to control where the concrete cracks. Cure for a minimum of 7 days before heavy traffic.
04Pergola over existing patio
A pergola over a concrete patio uses surface-mount post bases anchored into the concrete with concrete anchors. Mark post locations, drill for the anchors per the post base manufacturer's specifications, and set the bases. Set posts in the bases, run beams between the posts at the top, and add rafters across the beams. Brace the structure diagonally in both directions before loading the overhead.
Marcus Webb is a general contractor and home maintenance writer based in Columbus, Ohio. He writes about the repairs and installs that come up every year in every house — the practical, repeating work that keeps a home livable.