Shed Interior Walls With OSB: Cutting Around Boxes and Doors

Drywall was ruled out for the interior walls of a 12×16 modern shed, where the insulation was already done. The reasons given: taping, mudding and sanding are messy, and results are hard to get right without experience. The alternative is 5/8 in. OSB at about $21.50 for a 4×8 sheet, which the video puts well under a dollar per square foot. Truss core, by comparison, can run between $4 and $6 per square foot depending on the type.

Choosing the material

A channel poll asked whether people prefer drywall, plywood, truss core or other for a shed or detached garage. The vast majority chose plywood, and many of those picking other named OSB. Either OSB or plywood comes down to look and cost.

The first sheet

The first full sheet has no electrical box. The wall measured 93 in., and the sheet is cut to 92 3/4 in. to leave a quarter inch of gap above the concrete so moisture can dry out. With no track saw, a piece of LP trim board serves as a straight edge for the circular saw guard, offset an inch and a quarter. A story stick marks the screw locations, which matters most if the wall will not be painted, so the screw lines stay straight.

Countersinking and fastening

A small countersink bit mounted on an impact driver is used on every hole, especially at the edges, to avoid blowing them out. The sheet is shimmed at the bottom, factory edge matched to factory edge where possible for a consistent gap, and centered on the studs.

Cutting around electrical boxes

For the next panel, a laser line level transfers the box corner location from the installed OSB. The sheet is secured, then a one-gang box is marked at 2 1/2 in. wide and 4 in. deep. A new wood blade on an oscillating tool cuts the outline, then the depth through the 5/8 in. OSB, and the result lines up with the box.

The door sheet

The most complex sheet has a single-gang outlet box, a dual-gang light switch box and half of a 36 in. door opening. Small screws in the door frame hold the sheet off the door and wall, and screws beside the factory edge close the gap between sheets before any cutting. The door cutout is offset about 1 in. inward from the frame for the reveal. The circular saw is set to 3/4 in. to barely pass through the 5/8 in. sheet, then the oscillating tool finishes the corners. The final sheet needs only the door cutout.

Painting or plywood

The OSB can be painted. Alternatively, 1/4 in. sanded plywood can go over the 5/8 in. layer, which lets you hang items without finding a stud and can be stained. It cannot be installed alone and is less forgiving than OSB, which hides imperfect lines.