How to Replace a Damaged Tongue & Groove Subfloor With Plywood

A tongue and groove flooring system can be used to install a strong and stable subfloor in your home. Each tongue along the edge of one plank interlocks with the groove on the next plank for a tight fit. However, if one or more of these planks should become damaged, such as from water damage, you may need to replace it with standard plywood if the original flooring is no longer available. This means creating an identical tongue and groove system of your own.

Plywood
Pry bar
Pliers
Tape measure
Table saw
Pencil

Instructions

- 1
  Pry up the damaged flooring planks using a pry bar. Pull out nails with pliers.
- 2
  Measure the width of the old plank, including the length of the protruding tongue.
- 3
  Use a table saw to cut the plywood to match the width you measured.
- 4
  Get the measurement for how far up the side of the original plank the tongue and groove system is located. Set your table saw to this height. Align the board with the saw, and use the blade to cut out a new groove.
- 5
  Flip the board around and draw a straight line on both sides to represent the location of the tongue. On the side of the board, draw two lines to represent the protruding tongue.
- 6
  Use the saw to cut away the wood from the side to the depth you marked on the top and bottom of the plywood. When you're done, you should have an even tongue sticking out the middle of the board's side.
- 7
  Insert the new tongue and groove plywood piece into the existing tongue and groove system on your floor.

DIY Crawl Space Supports for Sagging Floors

How to Repair Carpet Tack Strip Holes in Concrete

Floor Repairs