I added a 10'x15' room and am preparing to hang drywall when I noticed the center of the engineered roof truss (15' span) is sagging slightly. The 2×4 trusses have a joint in the bottom center. If I put a 4' straight edge on one side, the gap about 3 foot out on the other side is ~1/4".
Talking with some friends we disagree on how to hang the ceiling drywall. Should the joint line up with the center of the truss or should the panel cover the center? Which would reduce the chance for cracking?
Note: Images are exaggerated for clarity.
Option 1: Joint in center
Option 2: Overlap center
Best Answer
Your trusses are defective and done very wrong and would only be used atop columns, supporting beam or bearing wall. Call the truss manufacturer for replacements that are built right, solid and seamless sticks on the bottom.
Sagging before even installing the drywall's load is a disaster ready to happen!
After that correction, then you can put your drywall joint on the truss for very wide butt-joint treatment. Or even better is, to put your joint between trusses and very shallowly "V" back-blocking framing for a tapered treatment.