How to Replace Individual Rotted Deck Boards

Decks are the workhorses of the backyard, but they spend every season fighting a losing battle against moisture, sun, and rot. When you spot a board that feels spongy underfoot or has visible fungal growth, it isn't just an eyesore; it's a structural liability that can lead to trips or collapses. Replacing a single board is far cheaper and faster than tearing up the entire deck surface. A job done well restores the integrity of your deck's walking surface while blending seamlessly with the existing wood. The goal is to isolate the damage, extract the board without harming the neighbors, and install the new piece with enough room to expand and contract. Keep your fasteners flush and your spacing consistent, and the patch will disappear into the rest of the floorboards within a few months of weathering.

Inspect Before You Act. Remove any furniture, planters, or rugs from the deck. Locate the rotted board and check the joist directly underneath to ensure the framing wood is still solid.
Pry Out the Rot. Use a reciprocating saw with a metal-cutting blade to carefully cut the nails or screws holding the board to the joists. Once the fasteners are cut, pry the board upward using a flat pry bar.
Size Your Replacement Right. Measure the gap left behind and cut a new board to size. Use pressure-treated lumber that matches the thickness and width of your current decking.
Seal Against Future Rot. Apply a generous coat of wood preservative or end-cut solution to the raw, cut ends of your new board. This seals the wood fibers against moisture where they are most vulnerable.
Secure With Precision. Lay the board into the gap and drive deck-rated screws through the face of the wood into the joists. Space the screws two per joist, ensuring they are driven flush with the deck surface.
Finish for a Seamless Blend. Wipe away any debris or sawdust from the site. If the deck is stained, wait for the new wood to dry out for a few weeks before applying a matching stain to blend the colors.