How to Build a Railing on a Deck

Deck railings are a fundamental piece from both a safety and appearance perspective. Railing is generally a mandatory safety feature for any deck higher than 30 inches above the ground. However, since local building codes vary, it is a good idea to check that your deck railing will meet code. Before assembly, refer to your deck plan, which should give you the railing details, including height of the baluster, post spacing and railing distance.

Step 1

Cut 4-by-4 posts and balusters with a circular saw by cutting the bottoms off at a 45-degree angle and sealing the ends with clear sealer. Drill pilot holes 2 inches apart through the bottom end of each post and two pilot holes spaced 4 inches apart near the bottom end of each baluster.

Step 2

Mark the position of the posts based upon your measurements and the deck layout drawing. Use a combination square to mark the outer edges of the post as a guide. Place the post within the guides with the angled end sitting flush with the bottom of the deck. Mark the post position on the side of the deck through the pilot holes.

Step 3

Drill pilot holes into the side of the deck. Attach the posts to the deck with lag screws and washers using a ratchet. Seal the screw heads with silicone caulk.

Step 4

Cut 2-by-4 side rails and position the edges so that they are even with the top of the posts. Use deck screws to attach the side rails to the posts. For adjoining side rails, cut the edges at 45-degree angles and drill pilot holes in the top boards. Hammer a nail through the pilot hole.

Step 5

Attach each baluster to the deck and the side rail using deck screws in the pilot holes. Use a spacer block to maintain consistent spacing between the balusters. Ensure the angled end of the baluster is at the bottom and flush with the bottom of the deck.

Step 6

Place a 2-by-6 board as a cap on the top of the side rail, aligning it so that it is flush with the inside edge of the posts. Place deck screws every 12 inches, into each post and into every third baluster. At the corners, miter the ends of the cap so that it is at a 45-degree angle and they align next to each other. Attach to the corner posts with deck screws.