Deck Repair

A deck is an extension of your home’s living space that needs little maintenance and few repairs. This Fix-It Guide on deck repair tells how a deck works, what often goes wrong, how to identify a deck problem, and what parts and tools you will need to fix it. It then gives instructions for how to refinish a deck, how to replace a deck step, how to add support to a deck joist, how to add bracing to a deck post, how to replace a deck baluster, and how to replace a deck post. These instructions may also apply to porch repair, gazebo repair, and other outdoor structure repair.

How Does a Deck Work?

Deck Repair

Components of a typical deck.

A deck is a flat or multilevel structure adjoining a house. It consists of a floor, horizontal joists, horizontal beams, and vertical posts. In addition, a deck typically has perimeter railings and stairs. Decks are constructed of decay-resistant wood (redwood, cedar), pressure-treated wood, or newer plastic materials, and are held together with fasteners.

What Can Go Wrong with a Deck?

From exposure to the weather, a deck’s protective finish will deteriorate and need renewing. Boards warp and sometimes are damaged. The edges of deck boards may become rough and unsightly. Steps may be damaged. Parts can loosen up.

How Can I Identify a Deck Problem?

  • If a deck’s surface has turned gray, you can renew its look and protect it by refinishing the surface (see below).
  • If a board has cupped up, just remove the board, flip it over, and re-nail it.
  • If a board is damaged, replace it with a new board that has weathered at the lumber yard. Alternately, you can age lumber by washing it with a solution of bleach and water and allowing it to dry.
  • If a step is damaged, you can replace it (see below).
  • If the deck bounces up and down, or sways, you can reinforce it (see below).
  • If a baluster or post is damaged, you can replace it (see below).

What Do I Need for Deck Repair?

Deck repair materials are available from local hardware, lumber, and paint stores or home improvement centers. The tools and materials you will need to fix it might include these:

  • Screwdrivers
  • Electric sander
  • Sandpaper block
  • Wood plane
  • Electric drill
  • Pressure washer
  • Hammer
  • Wrenches
  • Paint brushes
  • Circular saw
  • Crosscut saw
  • Combination square
  • Pry bar
  • Bleach
  • Broom
  • Galvanized screws and nails
  • Measuring tape
  • Level
  • Lumber
  • Stain
  • Wood preservative
  • Wood sealer

Fix-It Tip

Make sure you apply an extra coat of preservative to the ends of any replacement deck pieces cut.

What Are the Steps to Deck Repair?

Refinish a deck:

  1. Use a hammer to refasten protruding nails.
  2. Trim raised edges with a sandpaper block, electric sander, or plane.
  3. As needed, clean gray or dirty wood with a solution of 1 cup bleach in a gallon of water. Apply with a brush or broom.
  4. Use a pressure washer to clean the deck, being careful not to damage the wood with excessive pressure.
  5. Apply stain or wood preservative following the manufacturer’s instructions.
  6. Apply wood sealer following manufacturer’s instructions.


Always wear a dust mask when cutting pressure-treated wood. The wood is soaked in various chemicals that can be released when sawdust is made.

 Deck Repair

Refasten protruding nails.

Replace a deck step:

  1. Use a hammer and pry bar to remove the damaged step.
  2. Cut new stair treads to fit, using a combination square to cut the ends square.
  3. Place the new stair treads on the stringers.
  4. Drill pilot holes in the treads where the fasteners will go so that they don’t split the treads.
  5. Nail or screw the treads to the stringers.

Add support to a deck joist:

  1. Cut lumber to duplicate the size and length of the existing joist, using a combination square to cut the ends square.
  2. Install the new joist against the old one and nail the ends in place.
  3. Fasten additional nails, in pairs, every 18 to 24 inches through the joists.
  4. Finish the repair by staining or painting to match the deck.

Add bracing to a deck post:

  1. Measure diagonally from post to post and cut the first brace.
  2. Set the brace in place and nail the higher end to one end post.
  3. Fasten the other end of the brace to the opposite end post.
  4. Nail the brace firmly to all posts.
  5. If necessary, add a cross-brace between the posts to form an X.
  6. Trim off excess wood at the ends.
  7. Finish the repair by staining or painting to match the deck.

Replace a deck baluster:

  1. Remove the damaged baluster by removing the screws or nails that hold it in place.
  2. Measure and cut a replacement baluster.
  3. Install the new baluster and use a level to make sure it is plumb (vertically straight).
  4. Fasten the baluster with nails or screws as needed.
  5. Apply wood preservative or finish that matches the deck.

Replace a deck post:

  1. Remove all components (handrail, baluster) attached to the post.
  2. Measure and cut a new post to the same length as the old one, using pressure-treated or decay-resistant wood.
  3. Install the new post, fastening it to the footing as needed.
  4. Install the handrail and side rails on the new post.
  5. As needed, apply wood preservative, stain, and sealer.