Replace a cracked or loose deck board
One cracked, soft or lifting deck board doesn't always mean a big repair. If the joists underneath are still solid, replacing the board can be a manageable afternoon job. Check those supports before you start. Poke the joists with a screwdriver. If it sinks in easily, the wood is soft, and that's a bigger repair than a new board.
How deck boards are held
Sun, rain and years of foot traffic are hard on deck boards. They crack along the grain, go soft where water sits, or lift at the ends as the fasteners work loose. Swapping one out is mostly about getting the old board off cleanly, making sure the joist underneath is still solid, and matching the spacing of the boards around it.
Why boards fail
Boards crack and split over time.
Nails work loose as wood expands and contracts.
Standing water rots boards from underneath.
High-traffic spots wear out first.
| What you see | Likely cause | Fix |
|---|---|---|
| Crack along the grain | Sun and weather | Replace the board if it's splintering or loose. |
| Soft spot that gives underfoot | Rot | Replace the board, and probe the joist below. |
| End lifting up | Loose nails or screws | Replace nails with deck screws closer to the end. |
| Board cupped, edges curling up | Moisture on one side | Flip it bark-side up, or replace it. |
| Screwdriver sinks into the joist | Joist rot | Call a deck pro before replacing boards. |
Swap the board
- Remove the fastenersBack out screws or pry up nails. A pry bar and a scrap block protect the neighboring boards.
- Lift out the boardPry the board up gently and remove it.
- Check the joistsPress a screwdriver into the joists underneath. If it sinks in easily, the wood is rotting and needs a pro.
- Cut and place the new boardCut the new board to length so each end lands on the center of a joist, match the gap to the other boards using a nail as a spacer, and set it in place.
- Screw it downDrive two exterior deck screws at each joist, about 3/4 inch from each edge.
- Seal the new boardBrush sealer onto the cut ends. Stain or seal the whole board to match once the wood is dry enough; new pressure-treated boards often need a few weeks first. Check the product's label. Redoing the whole deck? The deck stain calculator works out how much to buy.
Watch it done
- The new board sits flat with a gap matching its neighbors
- It doesn't lift or rock when you step on the ends
- Two screws hold it at each joist
- The cut ends are sealed
If it doesn't look right
If the new board looks too different, a deck stain can help it blend in after it dries for a few weeks.
If a board keeps lifting at the end, add a screw closer to the end, or swap the nails for screws. The same fix works on a loose fence board.
What a pro typically charges (a rough estimate; prices vary by area): A deck repair pro typically charges $150–$400 to replace a few boards.
Find deck repair near you