How to Build a Wooden Deck from Scratch

Building a wooden deck requires careful planning, proper foundation work with concrete footings, framing with pressure-treated lumber, and finishing with decking boards - expect 3-5 days for a basic 12x16 deck.

1. Get Permission Before You Dig. Draw your deck design with exact dimensions and check local building codes. Most decks require permits, especially if attached to your house or over 30 inches high. Submit plans to your building department and wait for approval before starting any work.
2. Plant Your Posts Deep. Use spray paint to mark where each post will go according to your plan. Dig holes 2-3 feet deep and 12 inches wide for concrete footings. Space them no more than 8 feet apart. The holes should extend below your area's frost line to prevent heaving.
3. Lock Posts in Stone. Mix concrete and pour into each hole, leaving 3-4 inches above ground level. Immediately set your pressure-treated posts into the wet concrete, checking they're plumb with a level. Let cure for 24-48 hours before continuing.
4. Anchor to the House First. If attaching to your house, locate wall studs and mark where the ledger board will go. Install flashing first, then bolt the pressure-treated ledger board to the house using lag bolts every 16 inches into studs. This board carries significant weight, so proper attachment is critical.
5. Build Your Main Frame. Use a water level or laser level to mark all posts at the same height, accounting for any slope needed for drainage. Cut posts with a circular saw. Install the outer rim joist by attaching it to the posts with carriage bolts, creating a rectangle frame with the ledger board.
6. Space Joists Evenly. Mark joist locations every 16 inches on center along the ledger board and rim joist. Install joist hangers at each mark on the ledger board. Cut floor joists to length and install them in the hangers, securing the other end to the rim joist with joist hangers or by toe-nailing.
7. Brace Everything Down. Install blocking between joists at mid-span for additional stability. Check that the entire frame is square by measuring diagonals - they should be equal. Verify all joists are level and properly secured before moving to decking.
8. Lay the Living Surface. Start with a full board along the house, ensuring it's perfectly straight. Leave a 1/4 inch gap between the board and house for drainage. Secure each board with two deck screws into each joist. Use a spacer to maintain consistent gaps between boards for expansion and drainage.
9. Trim Edges Straight. After all decking is installed, snap a chalk line along the edges and trim excess material with a circular saw. Use a sharp blade designed for pressure-treated lumber to prevent tear-out and ensure clean cuts.
10. Install Code-Compliant Rails. Install railing posts every 6-8 feet, securing them with carriage bolts through the rim joist. Add top and bottom rails, then install balusters spaced no more than 4 inches apart per code. Build stairs using stringers cut to proper rise and run, typically 7-inch rise and 11-inch run.
11. Seal and Celebrate. Sand any rough spots and apply deck stain or sealer according to manufacturer's instructions. Clean up the work area and schedule your final building inspection. Once approved, your deck is ready for furniture and enjoyment.