How to Build a Deck

Planning and Permits

Before you break ground, check your local building codes and permit requirements. Most municipalities require permits for decks over a certain height or size. Draw a detailed plan including dimensions, post locations, and material specifications.

Consider your deck's orientation — south-facing decks get more sun, while north-facing stays cooler. Account for existing trees, drainage patterns, and access points for material delivery.

Choosing Materials

The three most common decking materials are pressure-treated wood, cedar/redwood, and composite decking. Pressure-treated lumber is most affordable ($2-4 per sq ft), cedar offers natural beauty ($4-7 per sq ft), and composite requires minimal maintenance ($6-12 per sq ft).

For the frame, use pressure-treated lumber or tropical hardwood. Choose galvanized or stainless steel hardware to prevent corrosion. Your decking board choice affects both appearance and long-term maintenance.

Foundation and Framing

Deck foundations typically use concrete footings with post anchors. The depth depends on your frost line — usually 12-48 inches deep. Space posts according to your deck size and local codes, typically 6-8 feet apart.

Frame with double beams at post tops, then install joists perpendicular to the beams at 16 or 24 inches on center. Use joist hangers for every connection and install blocking between joists for stability.

Installing Decking Boards

Start decking installation from the house side, working outward. Leave a 1/8-inch gap between boards for drainage and expansion. Stagger end joints across different joists for a stronger, more attractive surface. Use two screws or hidden fasteners at every joist crossing.

Railings and Stairs

Railings are required for decks over 30 inches high. Most codes require rails at least 36 inches tall with balusters spaced no more than 4 inches apart. For stairs, calculate rise and run carefully — typical step dimensions are a 7-inch rise with an 11-inch tread.

Finishing and Sealing

If using wood decking, apply a water-repellent sealer or stain within a few weeks of installation. Clean the deck first and apply on a dry day above 50°F. Reapply every 1-3 years depending on climate and sun exposure.

Pro Tips

Summary

Building a deck is a significant project, but careful planning and the right materials ensure lasting results. Use our deck calculator to estimate materials and costs, then follow this guide step by step.