Notwithstanding the provisions of section 25.02.01 of this article, sections 1710 and 1710.1 are added to, and chapter 35 of the Building Code is amended, to read as follows:
1710 General. The vertical load-bearing capacity, torsional moment capacity and deflection characteristics of joist hangers shall be determined in accordance with ASTM D 1761 and ASTM D 7147 as specified below using lumber having a specific gravity of 0.49 or greater, but not greater than 0.55, as determined in accordance with AF&PA NDS for the joist and headers.
Exception: The joist length shall not be required to exceed 24 inches (610 mm).
1710.1 Vertical load capacity for joist hangers. The vertical load-bearing capacity for the joist hanger shall be determined by testing a minimum of three joist hanger assemblies as specified in ASTM D 1761 or ASTM D 7147. If the ultimate vertical load for any one of the tests varies more than 20 percent from the average ultimate vertical load, at least three additional tests shall be conducted. The allowable vertical load-bearing of the joist hanger shall be the lowest value determined from the following:
1. The lowest ultimate vertical load for a single hanger from any test divided by three (where three tests are conducted and each ultimate vertical load does not vary more than 20 percent from the average ultimate vertical load).
2. The average ultimate vertical load for a single hanger from all tests divided by three (where six or more tests are conducted).
3. The average from all tests of the vertical loads that produce a vertical movement of the joist with respect to the header of 1/8 inch (3.2 mm).
4. The sum of the allowable design loads for nails or other fasteners utilized to secure the joist hanger to the wood members and allowable bearing loads that contribute to the capacity of the hanger.
5. The allowable design load for the wood members forming the connection.
Amend the Reference Standards in Chapter 35 for ASTM as follows:
D 1761-88(2000) ε 1 | Test Method for Mechanical Fasteners in Wood | 1711.1.1 1711.1.2 1711.1.3 |
D 7147-05 | Standard Specification for Testing and Establishing Allowable Loads of Joist Hangers | 1711.1.1 1711.1.2 |
(Ord. 0-19-1357, 11-13-2019; amd. Ord. O-22-1400, 1-11-2023)