As your wood deck ages, the boards may begin to rot, crack, or separate. This is especially true if the deck planks have not been cleaned, stained, and sealed on a regular basis. Deck board repair may be as simple as tightening a few screws, but rotten or damaged boards must be replaced.
This is a simple do-it-yourself project that does not require a permit or, in most cases, the reconstruction of the deck's structure, as the posts and joists are not directly exposed to the elements and typically outlast the decking. You will save a substantial amount of time and money by replacing only the worst deck boards as opposed to the entire deck.
How Much Does It Cost to Replace Deck Boards?
Your homeowner's insurance may cover the cost of repairing or replacing a storm-damaged deck. The cost of replacing deck boards is proportional to the number of boards replaced and the price of the wood used. A single 5/4 (1-5/32-inch) pressure-treated deck board measuring 6 inches wide and 16 feet long will cost approximately $23. The same deck board in cedar will cost approximately $58, but a comparable composite deck board costs approximately $42. A 5-pound box of coated #10 3-1/2-inch deck screws (about 240 screws) costs approximately $27. Similar stainless steel screws are roughly twice as expensive.
Circular Saw / Jigsaw / Oscillating Multitool / Reciprocating Saw
Screw Gun / Power Drill
Pry Bar / Cat’s Paw
Replacement Deck Boards
Deck Screws: Coated or Stainless Steel Wood Sealant / Stain (only for use on wood decking)
The new deck boards should mirror the aesthetic of the existing ones. If you are uncertain of the wood species used, smell a fresh cut. The scents of pressure-treated wood, cedar, and redwood are prominent. Try to determine the manufacturer or brand of composite decking and then match the color and design on the company's website or at retail.
How to Remove Deck Boards & Replace Them
Remove the Bad Boards from the Deck
Determine which deck planks need replacement. If you are not removing the entire board, determine where cuts will be made. Offset the cuts by at least one joist space from the ends of adjacent boards, and ensure that the leftover section of the old deck board, if any, and the new board span at least two joist spaces. Use a pencil and speed square to draw the cut line. Using a circular saw, remove the damaged deck board either flush with the joist or along the joist's centerline. Use a jigsaw or oscillating multitool to complete the cut to prevent cutting notches into the adjoining boards with the circular blade. If you are cutting along the joist's centerline, remove any nails or screws from the cutline or reposition it to avoid them.
When removing a board with a pry bar, place a block of wood underneath it to protect surrounding boards. If you are unable to remove a screw due to a stripped head, use an oscillating multitool or reciprocating saw to cut it flush with the joist. Use a cat's paw to pull or trim deeply embedded nails.
Inspect the Joists, Beams, and Posts
By removing the deck planks, the joists and beams will become visible. Examine them for decay or other damage and ensure that they are securely attached to the pillars and ledger board. Additionally, inspect the joists for decay, especially if they touch the ground. Verify that the joist hangers are level, rust-free, and complete with all fasteners. If you discover rot in any structural component, you must determine whether to repair or replace it and understand how to avoid and prevent future rot.
Add Support Cleats & Reinforcing Joists
Add cleats or sister joists, if necessary, to support the replacement deck boards and reinforce the damaged joists. Attach the cleat/joist with framing nails or structural screws to the existing joist where you cut off a deck board and to any other joist that needs reinforcing. Ensure that the top of each cleat/joist is flush with the existing joist's top. Apply a sealant to the top of the joists to prevent decay.
Cut the New Deck Boards
Determine the spacing between the existing deck boards. If possible, bridge the distance with a single board and leave a 1/8-inch expansion space at each end. Each board should span a minimum of two joist spaces, and cuts should be staggered with adjacent boards. Avoid making cuts that would leave knots at the board's ends.
Apply Stain (optional)
The application of paint or stain can add years to the lifespan of new deck boards. It will also aid in blending the new boards with any existing deck boards. If you are using wood that receives stain/paint badly, such as pressure-treated wood, you may need to let the boards cure for several weeks before applying a finish. Additionally, sanding the boards might help the stain or paint adhere. Coat the end grain of the wood planks. Combining one (1) cup of baking soda with one (1) gallon of water, scrubbing the solution into the wood, and rinsing it off will give the wood a weathered appearance similar to that of the current boards. Allow the board to dry before applying a finish or installing it.
Install the New Deck Boards
Installing the new boards with the bark side up will keep cupping from occurring. This will cause the grain pattern to be convex. Deck screws measuring 3 1/2 inches in length should be used to secure the boards. Drilling pilot holes will make the job simpler and will help to prevent splitting, particularly at the board's ends where the holes will be drilled. When you are installing the new boards, check to see that there is a consistent distance between each pair of boards.