How to Repair Deck Railings

A railing gives a deck a nice feeling of enclosure and makes it safer as well.

Replacing a baluster

In fact, most building codes require you to put a railing around any deck 30 inches (76 cm) or more above the ground. But a railing can't do its job if it has broken or missing balusters, or wobbly handrails or posts. Deck parts are fairly standard, so there's a good chance you'll be able to find premade pieces at your lumberyard that will make the repairs below as easy as possible.

Remove the damaged baluster by backing out its screws using an electric drill with a screwdriver bit. If it's nailed on, hammer near the top of the baluster on the opposite side of the nails to loosen them, then pry off the baluster with a hammer or pry bar. (Note: In some deck railings, the balusters are attached to a rail on top and to the end joist of the deck on bottom.)

Cut a replacement baluster to the length of the old baluster. The ends should be cut at a 45-degree angle; use a power miter saw or a saw and a miter box.

Hold the new baluster in position against the rails, centered between the balusters on either side. The angled cuts on the ends will be facing outward.

With a 1/8-inch (3-mm) drill bit, make a pilot hole through the baluster at each end, drilling through the flat front about 1/2 inch (12 mm) from the angled ends, and into the rails.


Drive a 2 1/2-inch (6-cm) galvanized screw into each pilot hole to attach the baluster to the rails (see A).

Apply wood preservative or finish if necessary.

Reinforcing a handrail

Cut a pressure-treated 2-by-4 scrap so that its length is the same as the width of the railing post. Use a power miter saw or a saw and a miter box.

Place the scrap inside the corner formed by the handrail and the railing post.

Using an electric drill with a screwdriver bit, drive two 3-inch (7.5-cm) galvanized screws through the block and into the post.

Drive one 2 1/2-inch (6-cm) screw down through the handrail and into the block, being careful not to run into the first two screws.

If possible, drive one 2 1/2-inch (6-cm) screw through the side rail or the side of the top rail into the end of the block.

Replacing a post

Detach the handrail and any long side rails from the post. Back out any screws holding them to the post; to remove nails, hold a wood scrap underneath the handrail or inside the rail, and hammer on the block until the nails release enough to be pried off.

Remove the old post from the base of the deck. This will require either removing nails as above or removing lag screws from the side of the post with a socket wrench.

Using the old post as a template, draw lines on a length of 4-by-4 lumber to replicate its length and shape.

Cut along the lines on the 4-by-4 with a handsaw, and cut out a notch in the bottom so that it will fit over the base of the deck and align with the remainder of the railing. Use a saw and a miter box (or a power miter saw) to make an angled cut at the bottom of the post.

Apply wood preservative to the inside surfaces of the notch.

Put the new post in place so that the handrail and side rails meet it at the proper places.

Drill two pilot holes through the bottom part of the post into the base of the deck.


Install two 5-inch (13-cm) lag screws with washers into the pilot holes; tighten firmly (see B).

Reattach the handrail and side rails to the new post, using 2 1/2-inch (6-cm) screws.

Apply wood preservative or stain to any new parts as needed.

Things You Will Need

  • 2-by-2 Lumber (or Premade Balusters)
  • 4-by-4 Lumber (or Premade Deck Railing Post)
  • Wood Preservative Or Finish
  • Scrap Of Pressure-treated 2-by-4 Lumber
  • 1/8-inch (3-mm) Drill Bit
  • 2 1/2-inch (6-cm) Galvanized Deck Screws
  • 3-inch (7.5-cm) Galvanized Deck Screws
  • 5-inch (13-cm) Lag Screws With Washers
  • Drill Bit For Pilot Holes
  • Electric Drill With Screwdriver Bit
  • Hammer
  • Handsaw
  • Power Miter Saw Or Miter Box And Saw
  • Pry Bar
  • Socket Wrench


  • While you're repairing the railing, consider installing some premade decorative post caps. They're available at lumberyards in a variety of designs.
  • Sometimes balusters on a fairly new deck become loose or cracked due to shifts caused by the deck's settling in the ground.
  • Apply an extra coat of preservative to the ends of any pieces you've cut on an angle.


  • When cutting pressure-treated wood (deck parts are often made from it), wear a dust mask to avoid inhaling any sawdust that may contain hazardous chemicals.
  • For safety, balusters should be spaced no more than 6 inches (15 cm) apart; install additional balusters, if necessary, to reduce any gaps to that size.