Everyone knows that member gaps can be caused by uncalibrated saws and poor jigging stops during truss set-up. But did you know the most likely cause of member gaps is the lumber carriage shifting or moving the lumber at an angle, thereby causing a skewed cut? This is especially true when a gang saw is employed. Even if one side hits hard, the opposite side of the truss may result in a member gap.
It is important to remember that this gap must be held to less than 1/8” for all member to member contacts, excluding floor truss chord splices which must be 1/16” or under. The photographs show examples of skewed cuts resulting in a member gap.
As the catcher is stacking lumber, he should have a calibrated framing square handy. The square should be used every 30 minutes, periodically to verify cuts throughout the day. If you don’t see a square close by to the catcher, you know he’s not aware of this requirement. Linear saws should also be checked, however, skewed cuts (in error) are rare.
So, if you’d like to ensure that you’re always producing high quality trusses, then you should remember to mind your (member) gaps and take corrective action as needed.