How to Lay Additional Plywood Subflooring

Most homes have plywood as a subfloor to allow a smooth, even surface for the finished flooring. If, over time, you have installed finished flooring over finished flooring you will have an uneven floor. Often, the best solution is raising the other rooms with lower floors by installing an additional plywood subfloor on the existing subflooring. Installing the subfloor correctly is important to ensure your subfloor is secure and will not squeak when you walk on it.

Tape
Circular saw
Vacuum
Construction adhesive
Caulking gun
Utility knife
Drill
2-inch deck screws

Instructions

- 1
  Measure the room with the tape measure and cut the plywood to the appropriate size. Use the circular saw to cut the plywood to size.
- 2
  Vacuum clean the existing plywood subfloor to remove all dust and debris.
- 3
  Put the construction adhesive tube onto the caulking gun. Cut the tip off the construction adhesive with the utility knife at a 45 degree angle.
- 4
  Apply a thick bead of construction adhesive in an "X" shape onto the bottom of the plywood.
- 5
  Put the plywood onto the existing plywood subfloor. Secure the plywood by putting a 2 inch deck screw every 12 inches. Keep installing the remaining pieces of plywood, by gluing them and securing them with deck screws. Clean the new plywood subfloor with the vacuum before installing the finished flooring on it.

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