OSB Tips and Tricks:osb-gap


Just as all things in life, better ways of improving accuracy and speed exist for almost everything in the construction industry.  Cutting rough openings in framed walls is no exception.  Sheathed walls are part of almost every home in the US.  Even in log homes, most often at least one window or door will be framed and sheathed.  A typical area for this to occur is the upper dormers, and often garages as well.
When you sheath a wall with OSB, or similar material it is an APA recommendation to leave 1/8” gap along all edges of the wall.
Slight expansion and contraction is common to all wood products as the engineered material will slightly change in composition due to water content, or lack thereof.  This 1/8” gap should also be taken into account with the rough opening frames of windows and doors.  Below is an easy approach to accomplish this goal as accurately, and as efficiently as possible.

osb-corner-markStep One: Marking the OSB

Working from the inside of the rough opening frame, and using an extended philips head screw bit, screw a 2” crew in the exact corner of the inside of the frame.  The extended bit is used to keep the screw from being driven in at an angle.  Drive four 2”+ screws in the corners of the RO.










Step Two: Marking OSB using screws

From the exterior of the wall, take a framing square on it’s edge and place it along the outside edge of two of the screws.  Then take a good framing pencil and mark the edge away from the screws.  With the thickness of the framing square and the pencil lead, the resulting mark should be about 1/8” from the edge of the framing on the R.O.



osb-sawStep Three: Removing OSB from opening

Once the mark is made, remove the screws from the corners, set the depth of the your circular saw to accommodate only the thickness of the OSB product you are using,  and cut the newly marked line.  Take care to not cut the framing of the window or door.  Setting the depth of the saw cut is key.  If any remaining material is holding the OSB, a small hand saw or “keyhole” saw makes for an easy way to remove excess material without damaging the frame.





Step Four: Finishing up

Push the newly cut material out of the window from the inside, or place a screw in the cut area of the panel to help grab the material and pull out using a framing hammer.  This method saves a few steps, and helps you accurately cut RO’s, while holding to the manufacturer specifications for 1/8” gap around the edge.

As always, comments are welcome.  We love to hear of new ways that make our builders lives easier!

Happy Building!