How to Replace Deck Plywood

Put that bad patch of plywood behind you with this deck-repair project.

Materials and Tools:

straightedge
hammer
pry bar
utility knife
calipers
push drill
caulking gun
spring clamps
paintbrush
paint roller
paint tray
power drill
circular saw
broom
scrap lumber
wood blocks
square
towel
dust mask
safety glasses
elastomeric textured coating
caulk
screws
primer
5/8-inch plywood

Steps:

1. Locate the seam lines around the edge of the damaged plywood piece. Line the straightedge up with the seams and make a cut through the anti-skid coating with a utility knife.

2. Use a square to mark the corners around the nail heads, and then use the straightedge to extend the lines to the next seam.

3. Cut through the seal coating along the joist, making a complete square.

4. Line up and temporarily attach a piece of wood to the deck to work as a guide for the circular saw.

5. Use calipers to measure the thickness of the plywood. Set the depth of the circular saw to that depth. Note: If you go too deep, you may cut the joist.

6. Wearing safety glasses and a dust mask, make a plunge cut for lowering the saw into the wood and making the cut. Don't cut beyond the boundary of the square.

7. Inspect the edge of the adjacent piece, making sure there's no water damage or rot. Make a series of small cuts in order to remove the damaged section of wood a little at a time.

8. Slide the new plywood to the edge of the hole. If necessary, mark for cuts so it will fit.

9. Line up and attach a piece of wood to the new piece of plywood to act as a guide for the circular saw, and cut plywood to fit.

10. Draw a line above the center joist as a marker for driving in screws.

11. Drill pilot holes for screws with a power drill, and then drive in screws with a push drill. Be sure to use galvanized deck screws rated for outdoor use.

12. Clean up debris, and caulk around the edge of the new piece, sealing the edges against weather. Smooth the caulk bead with a finger.

13. Caulk along the edge of the new seam, and smooth the bead with a finger.

14. Apply a coat of primer, and then apply textured coating with a roller. Allow the coating to dry for 24 hours, and then roll on a second coat.