A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
In Situ Nail Withdrawal Strengths in Wood Residential Roofs
A study was conducted to determine the in-place withdrawal capacities of nails in existing residential wood roofs. A field investigation project carried out by the Florida Coastal Monitoring Program collected data from 1400 nails tests in situ at 17 Florida homes, using a portable device to measure withdrawal capacity. The results reveal nail withdrawal capacities well below the values determined by the National Design Specification (NDS) empirical equation. A modified portable nail extractor (m-PNE) was developed and used to determine the withdrawal capacity of residential roof decking nails, and to provide added data to explain low values. Concurrently, laboratory tests were conducted on approximately 1300 6d common galvanized nails installed in southern yellow pine (SYP) framing members, using the m-PNE and the standard test protocol method (ASTM D1761) for a benchmark comparison. The m-PNE mean nail withdrawal capacities were 30% lower than the withdrawal capacities obtained following ASTM D1761. Test results suggest that the measured nail capacity is influenced by the method of localized sheathing removal to access the nail head. While some loss in strength may be due to environmental factors and aging, it is suggested that driving nails through sheathing may contribute to lowered capacity. Preliminary results suggest that actual factor of safety for nail withdrawal is likely smaller than the 5.0 assumed in the NDS, indicating less conservatism than intended.
In Situ Nail Withdrawal Strengths in Wood Residential Roofs
A study was conducted to determine the in-place withdrawal capacities of nails in existing residential wood roofs. A field investigation project carried out by the Florida Coastal Monitoring Program collected data from 1400 nails tests in situ at 17 Florida homes, using a portable device to measure withdrawal capacity. The results reveal nail withdrawal capacities well below the values determined by the National Design Specification (NDS) empirical equation. A modified portable nail extractor (m-PNE) was developed and used to determine the withdrawal capacity of residential roof decking nails, and to provide added data to explain low values. Concurrently, laboratory tests were conducted on approximately 1300 6d common galvanized nails installed in southern yellow pine (SYP) framing members, using the m-PNE and the standard test protocol method (ASTM D1761) for a benchmark comparison. The m-PNE mean nail withdrawal capacities were 30% lower than the withdrawal capacities obtained following ASTM D1761. Test results suggest that the measured nail capacity is influenced by the method of localized sheathing removal to access the nail head. While some loss in strength may be due to environmental factors and aging, it is suggested that driving nails through sheathing may contribute to lowered capacity. Preliminary results suggest that actual factor of safety for nail withdrawal is likely smaller than the 5.0 assumed in the NDS, indicating less conservatism than intended.
In Situ Nail Withdrawal Strengths in Wood Residential Roofs
Shreyans, Sushmit (author) / Kerr, Ashlie (author) / Prevatt, David O. (author) / Gurley, Kurtis R. (author)
ATC & SEI Conference on Advances in Hurricane Engineering 2012 ; 2012 ; Miami, Florida, United States
Advances in Hurricane Engineering ; 1017-1026
2012-11-13
Conference paper
Electronic Resource
English
In Situ Nail Withdrawal Strengths in Wood Roof Structures
| British Library Online Contents | 2014
In Situ Nail Withdrawal Strengths in Wood Roof Structures
| Online Contents | 2014
| British Library Conference Proceedings | 2010