3004 Chapter 24 



24-12 NAIL- AND SCREW-HOLDING CHARACTERISTICS 



NAIL HOLDING 



Sheathing and decking are usually secured to supporting rafters, wall studs, 

 and joists by nails. Shingles and siding are nailed to sheathing, and hardwood 

 flooring may be nailed to decking. 



Nailing characteristics of interest are therefore driving resistance, withdrawal 

 resistance, lateral resistance, and tendency of nails to "pop" or work loose. 



Driving resistance. — Flakeboards made from southern hardwoods are more 

 dense (44-46 Ib/cu ft) than southern pine plywood (about 36 Ib/cu ft) and 

 therefore nails are somewhat more difficult to drive in the flakeboard. This is not 

 perceived as a major obstacle to use because nailing guns, which work well on 

 flakeboard, are much used to attach sheathing and decking to structural support- 

 ing members. Shingles, siding, and hardwood flooring being nailed to sheathing 

 or decking give some support to nails permitting hammer driving without undue 

 difficulty. 



Withdrawal and lateral resistance of 6d nails. — Pages 1224 through 1270 

 of Koch (1972) describe in considerable detail factors affecting withdrawal and 

 lateral resistance of nails in southern pine wood. Minimum lateral and withdraw- 

 al loads for 6d common nails with which APA RATED SHEATHING 1/2-inch 

 and less in thickness is attached to supporting structure are specified in table 24- 

 8. Minimum fastener performance for APA RATED STURDI-FLOOR is the 

 same as the subfloor minimums shown in table 24-8. Data available suggest that 

 flakeboard made from southern hardwoods readily meets these specifications 

 (table 24-22). 



Table 24-22. — Ultimate withdrawal and lateral resistance of 6d common smooth- 

 shanked nails driven through I /2 -inch-thick flakeboard and southern pine plywood' 



Statistic and 

 exposure condition Flakeboard^ Plywood'^ 



Pounds 



Withdrawal load 



Dry 158 81 



Wet/redry^ 75 52 



Lateral load 



Dry 748 439 



Wet/redry'^ 489 246 



'Tested according to ASTM D 1037-72 (American Society for Testing and Materials 1975a). Data 

 from study files of FS-SO-3201, Southern Forest Experiment Station, Pineville, La. 



^Three-layer, mixed-species flakeboard with randomly-oriented flakes fabricated according to 

 optimum procedure of Hse et al. (1975); see footnote of table 24-12 for summary. Density, based on 

 ovendry weight and volume, was 50 pounds/cu ft. 



Three-ply CDX southern pine plywood purchased in central Louisiana. Density based on 

 ovendry weight and volume was 36 pounds/cu ft. 



■^Wet/redry is exposure to 24 hours of continuous soak followed by testing dry. 



