Diaphragm Construction Continued
Floor diaphragms and roof diaphragms may be constructed with plywood or OSB sheathing panels oriented in one of six ways, as described and illustrated below:
- Case 1 -short direction (4 ft dimension) of sheathing panels oriented parallel to applied lateral load; adjacent lines of sheathing are staggered so that panel joints in the direction of the applied lateral load are discontinuous
- Case 2 - long direction (8 ft dimension) of sheathing panels oriented parallel to applied lateral load; adjacent lines of sheathing are staggered so that panel joints in the direction of the applied lateral load are discontinuous
- Case 3 - long direction (8 ft dimension) of sheathing panels oriented parallel to applied lateral load; adjacent lines of sheathing are staggered so that panel joints perpendicular to the direction of the applied lateral load are discontinuous
- Case 4 - short direction (4 ft dimension) of sheathing panels oriented parallel to applied lateral load; adjacent lines of sheathing are staggered so that panel joints perpendicular to the direction of the applied lateral load are discontinuous
- Case 5 - short direction (4 ft dimension) of sheathing panels oriented parallel to applied lateral load; adjacent lines of sheathing are not staggered, resulting in continuous panel joints (grid pattern) both parallel and perpendicular to the applied lateral load
- Case 6 - long direction (8 ft dimension) of sheathing panels oriented parallel to applied lateral load; adjacent lines of sheathing are not staggered, resulting in continuous panel joints (grid pattern) both parallel and perpendicular to the applied lateral load
Since the various diaphragm construction cases described above are dependent on orientation of continuous panel joints with respect to the direction of applied lateral load, it is apparent that a Case 1 diaphragm for applied lateral load on one edge will be a Case 3 diaphragm for applied lateral load on the orthogonal edge of the diaphragm. Similarly, a Case 2 diaphragm in one direction is a Case 4 diaphragm in the orthogonal direction, and a Case 5 diaphragm in one direction is a Case 6 diaphragm in the orthogonal direction.