1.Panel roof sheathing shall be (specify appropriate grade):

APA RATED SHEATHING EXP1

APA RATED SHEATHING EXT

APA RATED SHEATHING/CEILING DECK EXP 1

APA STRUCTURAL I RATED SHEATHING EXP 1, or

APA STRUCTURAL I RATED SHEATHING EXT.

Sheathing permanently exposed to weather shall be classed Exterior.⁽⁵⁾

Install with the long dimension or strength axis of the panel across supports, except where noted^(8), and with panel continuous over two or more spans. for pitched roofs, place screened surface or side with skid-resistant coating up if OSB panels are used. Wear skid-resistant shoes when installing roof sheathing and keep roof deck free of dirt, debris and sawdust during constructions. Suitable edge support shall provided where indicated on drawings (or in recommendations of APA)⁽⁶⁾ by use of panel Clips, tongue-and-groove edges, or lumber blocking between joists. Panel  end joints shall occur over framing.

Spacing of 1/8" is recommended at all panel ends and edges, unless otherwise indicated by the panel manufacture.⁽⁹⁾

Nail 6" o.c. long supported panel edges and 12" o.c. at intermediate supports, except that when supports are spaced 48" o.c. at all supports. Use 8d common nails, except that when panels are 1-1/8", use   ring-shank or 10d common^{.(10)(11)(12)}

Cover roof sheathing as soon as possible with roofing felt or shingle underlayment for protection against excessive moisture prior to roofing applications.

C. Floors

1. Subflooring (under structural finish floor such as wood strip or underlayment)- Panel subflooring shall be (specify appropriate grade):

APA RATED SHEATHING EXP1

APA RATED SHEATHING EXT

APA STRUCTURAL I RATED SHEATHING EXP 1, or

APA STRUCTURAL I RATED SHEATING EXT

Install with the long dimension or strength axis of the panel across supports and with panel continuous over two or more spans. Panel end joints shall occur over framing. Spacing of 1/8" is recommended at panel ends and edges, unless otherwise indicated by the panel manufacturer.⁽⁹⁾

Nail 6" o.c. along supported panel edges and 12" o.c. at intermediate supports with 6d common nails for panel 1/2" or less, 8d for greater thickness. Where panels are 1-1/8" thick and supports are 48" o.c., nails shall be 8d ring-shank or 10d common and spaced 6" o.c. at all supports ^(10)(11)(12)