Subfloor Repair Video
You are in the middle of a remodeling project and you have a hole in the floor. The floor does not have access from below, so all the repairs have to be from above. Here are some simple tips to help with that repair.
First thing to do is square up the opening. Use a framing square to mark lines to create a nice square or rectangular opening. Next, cut a piece of flooring to match the opening. Be sure the patch material is the same thickness as the subfloor. If the wood patch is about an 1/8" smaller than the opening, that is okay.
If there is a floor joist available, attach a 1x3 to the joist and flush with the top of the floor joist. After that is attached, take a 2x4 about 6" longer on each end then the opening. Drill two holes in the center of the 2x4. These will be used to hold the board up with your fingers, like a bowling ball. While holding it in place, drive 2" long screws down through the subflooring and into this piece of wood. This 2x4 will hold the patch in place and prevent it from falling down.
Finish the patch by taking the board you cut to fit the opening and screw it into place. The floor is now ready for you to continue with your project.