Observation: Roof is wavy from bowed sheathing.
Performance Standard: Roof sheathing shall not bow more than ½ inch in 2 feet.
Corrective Measure: The remodeler will straighten bowed roof sheathing as necessary to meet the performance standard.
Discussion: The remodeler usually can meet this performance standard by using thicker plywood sheathing (either 1/2 inch or 15/32-inch span-rated, not 3/8 inch) with more plies (5 not 3) or wafer board and plywood clips (a) to align adjacent sheets between trusses or rafters and (b) to ensure room for expansion of the sheets. In rare instances, the remodeler might have to install blocking between the trusses to straighten the sheathing.
