How to Replace a Damaged Section of Subflooring

Do you have a section of flooring that has had water damage and needs replacing? Are you wondering if you can replace just that section without tearing out the entire floor?

The answer is yes, you can. As long as you provide adequate support at all the seams, you can replace only the bad section.

To begin, remove the top floor covering to reveal the total amount of floor damaged. If you are going to be able to reuse the top covering, carefully remove it or pull it back so that you will have room to work.

Once you can see how big an area needs to be removed, locate the joists on either side of the damage floor. Using a large ruler, four foot level, or anything that will help you draw a straight line, draw out a square going from the middle of the joist on one side to the middle of the joist on the other side. By cutting at the center of the joist you will have enough room to nail or screw the new section of flooring to the joists.

Adjust your circular saw to cut the depth of the flooring to be removed. Carefully cut out the damaged section of flooring. Remove any nails or sawdust from the joists.

Using a section of plywood or particle board the same thickness as the original floor, draw out and cut a piece to fit your opening.

Now, although you have something to nail or screw the new piece to on the joists, you still need some kind of a brace or support to nail to on the other two sides. Measure the distance between two joists. Cut a piece of 2 by 4 that size. Place it between the two joists, centering it half under the edge of the original floor and toe nail or screw it to the joist. Cut support pieces to fit between all the joists in the cut out section and nail or screw them in. Be sure to center them, leaving half for the new section of flooring. You now have support for the new section.

Before placing the cut section of plywood into the opening, mark the center of all joists on either side of the cutout. This makes it easy to draw or chalk a line down the new piece once it is in place so that you know exactly where to place your nails or screws.

Place your new section of flooring into place. Using the marks you made in the previous step to show the location of the joists, draw or chalk a line down the new piece. You can now attach the new piece easily and with confidence that you are hitting the joists and supports. Don't forget to nail or screw the old flooring at the edge of the cutout.

Congratulations. You have now replaced that damaged floor with a new section. You're ready to re-apply or install a new floor covering.