As code expert Glenn Mathewson explains, a lot of the “rules” handed out by inspectors don’t actually come from the code. Rather, they come from manufacturers’ installation instructions. The code references these instructions 381 times in the 2018 IRC and the directives within carry the authority of the code. That’s just the low-hanging fruit, however. Many products are not mentioned in the code and are approved as alternatives. For those approvals, a product must be tested and the installation instructions provide the only manner in which their tested performance can be duplicated with assurance. These rules aren’t printed in the big code books the inspectors should be referencing. These rules belong to the contractor installing these products, and their common absence on the jobsite is a recipe for lost time. Those rules – those instructions – are paper tools that can save you time from a failed inspection.
Mathewson recommends that a custom deck builder should carry with him a 3-ring binder that contains all the specifications, listings, code-approval reports, and installation instructions for every product used on a job. This could include the identification tags from the ends of treated lumber; the fastening pattern tables for structural screws; the installation instructions for composite decking, with maximum joist spacing and other information; the load tables and installation requirements for joist hangers and other metal hardware; UL listing for stairway lighting; the mounting bracket fastening for extruded aluminum guards; and other examples of “code requirements” via installation instructions. True, many inspectors may not care about these things, but if they were to start making assumptions, wouldn’t it be helpful to have a tool to set things straight and avoid lost time from a failed inspection or follow-up inspection? Read more.