DIY Network

Prepping Plywood Subflooring

This DIY Basic will provide tips on prepping plywood subflooring.

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Step 1: Watch an Overview Video

Step 2: Gather Your Materials and Tools

Materials and Tools:

self-leveling compound
long level
power drill
wood screws
pry bar
measuring tape
carpenter's square
chalk line
utility knife
sharp screwdriver
circular saw
safety goggles
butcher paper
construction adhesive
drywall screws
wood putty
fine-grit sandpaper
soft mallet and tapping block
shoe molding
finish nails

Step 3: Prep the Floor

A bad or uneven subfloor can ruin the look of new hardwood. Before you install, your subfloor must meet four basic requirements: clean, level, dry and structurally sound.

Start by removing existing baseboards, molding and flooring.

Fill dips in plywood subfloor with leveling compound.

Use a long level to check the floor for level.

Loose or squeaky boards should be screwed tight.

Step 4: Identify and Mark Damaged Plywood

Use utility knife or sharp screwdriver to identify damaged wood.

With chalk line, mark spots to be cut out.

Use carpenter's square to square replacement areas.

Cuts parallel to joists must be fall on top of joists.

Nail heads will show location of joists.

As an alternative, cut beside joist and nail 2x4 to side for attaching new plywood.

Step 5: Remove Damaged Plywood

Locate wiring and plumbing.

Set saw blade 1/4 inch deeper than subfloor and cut along chalk lines. If damage is too near wall for saw to reach, cut subfloor with hammer and chisel.

With pry bar, remove damaged plywood.

Step 6: Cut and Install New Plywood

With butcher paper, make templates of areas to be replaced and trace onto new plywood.

Cut out new plywood sections. New plywood must be same thickness as old.

Apply construction adhesive to exposed floor joists.

With drywall screws, screw new plywood to joists.

Step 7: Add the Finishing Touches

Fill gaps with wood putty and sand smooth.

Check clearance at doorways and transitions to make sure floor will accommodate hardwood.

Tip: Some types of hardwood flooring must be acclimated to installation space for up to 48 hours.

Nail shoe molding to wall, not floor.