How to repair a large hole in OSB?

Question

I know that it's just the garage but I'd like to repair this approximately 5 inch hole in an interior OSB partition wall. How should I proceed?

Answer 1

Turn off the power feeding that outlet and move the wires out of the way. Set the blade on your circular saw to make a cut just a little bit deeper than the OSB is thick. From the opposite side of the wall than what is shown in the picture, cut a rectangle out of the OSB that includes the top and bottom of the hole and extends to the middle of each stud to either side. Cut a piece of OSB to fit the hole, and screw it into the studs.

Alternatively, if you don't want to see a patch, you can just take off the whole piece of damaged OSB and replace it with a new one.

Answer 2

I think you'd prefer to do patch from inside only, yes?

1. Cut out a slightly larger rectangular opening of some nominal dimensions say 2"H and 4"vert. use small torpedeo level or small framing square to get sides parallel.
2. Back support patch: Cut out a patch that is the same width but 4 inches longer as the cutout in step 1.
3. Flush patch: cut out a patch that is the same width and length at the hole in step 1, undercut it slightly, 1/16 to 1/8 smaller, for ease of fit.
4. put a 1 1/4 drywall screw at 2" above the bottom and one at the center of the back support patch. Tighten both screws only enough to make them sturdy, but don't run them down. The bottom screw will hold the back support on the lip of the hole, the center one will help you hold it flat during installation of the back support piece. Both screws will be removed later.
5. Drill and countersink 4 pilot holes for your back support patch 1" above and below cutout hole of step 1. These are clearance holes and are not meant to hold the screws
6. Install some construction adhesive to the top 2" and the bottom 2 inches of the back support patch.
7. Take the back support patch from step 6, holding both screws and install it on the back (through to the inside of the wall cavity) side of the cutout, resting the bottom screw on the cutout bottom lip and pulling both screws out manually to set adhesive. While holding the nearest screw tight, install 2 drywall screws top and 2 screws bottom in the holes from step 5. Tighten them down flush, but don't over-tighten. OSB will strip. Remove the 2 pull down screws.
8. Install the flush patch over the back support patch with more adhesive and 2 more screws

You should have a solid, flush, matching patch when through.

PS A keyhole saw will enlarge the hole for the fewest $/use. I doubt any circular saw would maneuver in there. My personal favorite is one of the OMTs (Oscillatory Multi Tools).