*FIR* 3/4"-4'x8' CDX 5-PLY PLYWOOD | 5-Ply Fir CDX Plywood Sheathing is designed for excellent performance. It is perfect for all traditional plywood panel Sheathing applications. Use appropriate fasteners at the recommended schedule and gap panels 1/8" on the ends and edges of each panel. For Roof Applications; do not exceed the span limitations printed on each panel. Check local building codes for panel edge support requirements. Without edge support, you may need to decrease the support on-center spacing to less than the span rating of the panel. Check local code for requirements. Exposure 1 rated for limited exposure.