Repairing Pine Stair Treads

Small Cracks

• 1

  Put on a face mask and safety glasses. Sand the stair treads with rough-grit sandpaper to remove the finish. Smooth down the raw surfaces with fine-grit sandpaper until they are even and free from splinters and pitch. Wipe down the pine stair treads with a tack cloth.

• 2

  Open any nearby windows or doors for ventilation. Fill in any surface cracks on the pine stair treads with epoxy caulk. Let the epoxy caulk set overnight. Sand down the stair treads with fine-grit sandpaper to remove any excess epoxy caulk.

• 3

  Walk on the treads and listen for squeaky or loose spots. Refasten the stair treads to the stringers with nails and a rubber mallet or screws and a screwdriver. Check the levelness of each stair tread with a builder's level.

• 4

  Place wood shims between the treads and risers on any stair that is not level. Gently hammer the shims with a rubber mallet until the treads are level. Break them off under the treads with your hands or with the mallet. Sand the shims with rough-grit sandpaper until you no longer can see them.

• 5

  Apply shellac with a paintbrush to the pine stair treads to ensure that no pitch leaks from the wood. Let the shellac dry overnight. Lightly sand the shellacked surfaces with fine-grit sandpaper. Wipe the stair treads with a tack cloth. Brush stain on each stair tread with a paintbrush, and let the surfaces dry for 24 hours before walking on them.

Large Cracks

• 6

  Wedge a small pry bar's tip between the damaged stair treads and their risers. Place a small wood block beneath the pry bar to minimize damage to the risers. Lift up on the pry bar, and remove each cracked stair tread.

• 7

  Flip the stair treads over. Measure the length of the cracks with a measuring tape. Cut patches from half-inch plywood with a bandsaw that will fit over the cracks. Attach the plywood patches on the underside of the stair treads with carpenter's glue. Let the glue dry overnight. Tighten the patches by drilling four guide holes with a drill and then attaching screws with a screwdriver.

• 8

  Run a bead of stair adhesive around the edges on the underside of each damaged stair tread and the tops of the risers. Press each stair tread back into place on the stringers, and nail or screw them down. Let the adhesive set for up to a week.

• 9

  Check the levelness of each stair tread with a builder's level. Place wood shims between the treads and risers on any stair that is not level. Gently hammer the shims with a rubber mallet until the treads are level. Break them off under the treads with your hands or with the mallet. Sand the shims with rough-grit sandpaper until you no longer can see them.