The Norbord experts, in collaboration with APA representatives, offer a solution for roofing panels which are lifting slightly.
All fasteners are critical. The ten “most important” fasteners in a roof panel are the ones in each corner and the six in the intermediate panel edge connections. The critical placement of these fasteners are key; spaced 3/8″ of an inch from the edge and corners.
If an installer can get the ten most important fasteners applied correctly it will make the remaining (twenty seven) fasteners do a better job. Conventional framing at 16″o.c. would of course have more fasteners.
This was the simplistic description that Roland Hernandez (APA rep) used when explaining how to eliminate the horizontal joint (8′ panel edge) telegraphing on a roof. This issue was accentuated by the misplacement of fasteners on the intermediate trusses. The framing crews were starting their nails 2 to 3 inches and as much as 6″ to 8″ from the edge of the panels (on the intermediate trusses).
This installation error caused the panel edge to lift slightly which created a slight shadow on the roof when the sun was at a certain angle. Typically this phenomenon is mistaken as an edge swell issue and is seldom identified or diagnosed as an installation problem.