Roofing Nail Performance In Structural Flakeboards

Phenolic structural flakeboard might be commonly used as roof and wall sheathing and as subfloor panels in housing. Important in the acceptability of such flakeboard as roof sheathing is the ability to hold the shingles in place. Failure of the roofing nails to perform this function is exhibited by nail "pop"—the slow natural withdrawal of a nail due to shrinkage and swelling of the panel and shingles. Such tendency of 1-inch roofing nails that had been driven into and through commercial and experimental flakeboards was compared with that in 5-ply exterior grade Douglas-fir plywood. Cyclic moisture conditions (including freeze-thaw) were generated employing an ASTM accelerated aging procedure. Nail pop was not evidenced in any of the panels. Rather, the nailheads were observed to subside further into shingle and panel surfaces with increasing exposure. This subsidence was highly correlated to the thickness swell of the panels. It can be concluded that nail pop will not be a problem with nails driven through the flakeboard

Effect of circumferential stiffeners on the buckling properties of thin, curved plywood panels in axial compression

Information reviewed and reaffirmed August 1961. This report was originally issued in February 1950