We’re seeing trends with new project tracking software hitting the market that promise to facilitate faster, more efficient, and cost-saving measures throughout the inspection process. In reality, replacing traditional inspection methods with new software can cause more confusion than efficiency. Unfortunately, several of the software packages being offered for project tracking make it difficult for outside suppliers to include “deferred documents” as accepted by the code. The results are red tags issued for engineered truss component solutions.
The main culprit is that labels in the field won’t match the truss placement diagram submitted at the permit stage. This really becomes an issue when dealing with the tract or volume builders. With a volume builder program, the plan series is submitted one time for approval and then used as a reference for a specific permit later. While this sounds simple, it can become frustrating to an inspector who may not fully understand components and what a truss placement diagram represents.
The purpose of a component manufacturer’s truss placement diagram at the time of submittal is to show the directional layout or proposed location of the truss components and the requirements for bearing. This information is then used to verify the framing of bearing walls, bracing plan requirements, and any beams. What if there is a change after the permit approval? If it is a structural change, such as bearing walls movement or new options affecting the bracing or foundation plans, then the new plans should be re-submitted for approval as part of the permit process. What if no structural modifications were made and cosmetic changes are only required? Should it matter if an interior, non-load bearing wall gets shifted an inch or the component manufacturer changes its lumber inventory due to market availability?
What often is misunderstood about component manufacturers is their need to make minor changes prior to final delivery. Even a change in lumber supply may cause a component design to reflect a different truss label than what was used in the permit’s set designed months earlier. This doesn’t mean the engineered components and bearing requirements have changed, only how the manufacturer builds its components. While there are no changes in the overall structure, there is a significant appearance of a change for the building official.
The Solution:
The IBC code addresses accepting deferred submittals and the requirement for the individual truss drawings at the time of delivery. In accordance with IBC Section 2303.4, the construction documents containing truss design drawings and truss placement diagrams shall be provided with the shipment of trusses delivered to the job site by a registered design professional. These documents shall be provided or made available to the building official prior to installation of the components. When component suppliers ship a project they typically send a delivery set of documents. Included with this set should be the actual component design and truss design drawing, which matches the project specifications and delivered components. Such documentation may also be made available electronically by the builder. For either option of delivery, this is the information that the field inspector should use to perform their final structural inspection. The provided documents will clearly identify all the bearing and permanent bracing requirements in accordance with sections IBC 2303.4 Trusses or IRC R802.10 Wood Trusses.
With the proper construction documents the inspection should go smoothly without the frustration of looking at something in the field that may not match the permit sets.
Paul G Johnson P.E.
Associate Director at Large, BOAT
Director of Technical Services, UFP San Antonio LLC