There is often confusion with regard to Inspection and Quality Assurance requirements for Metal Plate Connected Wood Trusses (MPCWT). There are several types of inspections described in the building codes and their referenced standard, ANSI/TPI 1. This guide will explain how each type of inspection applies to MPCWT. 

Step-by-Step

Intro

Introduction

  • There are often questions as to whether trusses require a special inspection.
  • This presentation will discuss the steps to determine what type of inspections a building with trusses might need

Step 1

Standard Building Inspection

  • Requirements are discussed in the IRC and IBC Chapter 1
  • Most buildings, including buildings with trusses, require a framing inspection by a Building Official.

Step 2

Special Inspections

  • Requirements discussed in IBC Chapter 17
  • Special inspections may be called for by the building inspector in a variety of situations.
  • Where required, special inspections are in addition to the standard building inspection.

  • There are only two situations listed in IBC Chapter 17 related to metal plate connected wood trusses that would require a special inspection:
    • High-load diaphragms
    • Metal Plate Connected Wood Trusses spanning 60 feet or greater

Step 3

Structural Observations

  • Requirements discussed in IBC Chapter 17
  • Structural observations are generally performed by registered design professionals
  • Where required, structural observations are in addition to the standard building inspection and any special inspections.

  • Structural Observations are generally reserved for building systems resisting high seismic and high wind forces
  • Unless the building containing trusses also falls into one of these categories, structural observations are not required

Step 4

In-Plant Third Party Inspection

  • Third party inspections are required by ANSI TPI 1, the truss design standard referenced by the building codes.
  • The third party QC process that many Truss Manufacturers employ is done at the plant, not at the jobsite