Safety-net supports on construction sites

November 23, 1977
Mr. Javier Larroquev
[Recipient address omitted]
Dear Mr. Allende:
This is in response to your letter received November 4, 1977, concerning the supports required for safety nets.
The Construction Industry Standards were originally published in the Federal Register as Part 1518, April 17, 1971. Since then, the Construction Standards have been recodified and published as Part 1926, and Section 105 still addresses safety nets. We have enclosed a copy for your information. The support of the safety net to the building is required by performance type standards in lieu of specification type standards. Nets are required to be hung with sufficient clearance to prevent user's contact with the surfaces of structures below, and such clearances shall be determined by impact load testing. In addition, edge ropes are required to provide a minimum breaking strength of 5,000 pounds and forged steel safety hoods of shackles shall be used to fasten the net to its supports.
The American National Standards Institute, Inc. (ANSI) promulgates standards intended as a guide to aid the manufacturer, the employer and the general public. The ANSI A10.11-1977 minimum requirements for safety nets recommends a test of dropping a 400 pound bag of sand, not more than 30 inches (+/- 2 inches) in diameter, from a height of 25 feet above the net into the center of the net without any broken strands or significant distortion of the net pattern or the suspension system.
In installations where there is not an applicable OSHA standard, the net supporting system is required to be installed and used only in accordance with accepted engineering practices. This would include such items as the manufacturers' specifications for the net support system, its use, and a safety factor based on the specific use. Otherwise, a violation of Section 5(a)(1) of the Act (copy enclosed) would be considered on a case-by-case basis.
If I may be of any further assistance, please feel free to contact me.
Sincerely,
John K. Barto, Chief
Division of Occupational Safety Programming
Enclosures