In-Plant Truss Inspection Highlights

The following highlights pertain to in-plant truss inspections.  As per ANSI/TPI 1-2014, Chapter 3, plants are to inspect a minimum of three trusses per set-up location per shift per week.  On the trusses selected for inspection perform a Preliminary Truss Inspection and Detailed Joint/Critical Joint Inspection(s) as outlined below and document your findings.  Plants should maintain a weekly inspection log or its equivalent to document that this provision has been met.

Preliminary Truss Inspection



Perform a preliminary inspection of the truss comparing the built truss to the truss design as shown on the truss drawing or engineering drawing.  Check both sides of the truss.  Items to check include:

  • Dimensions
  • Lumber grade
  • Member-to-member gaps
  • General plate embedment
  • General member defects
  • General plate rotation

Record all of your inspection observations on the truss or engineering drawing checking each items off as you go and making note that you checked the item and indicate any variances.  Record a summary of your findings on the TPI Inspection Formwork.  To help with your inspection needs in addition to the TPI Inspection Formwork, TPI has developed some additional QC in-plant inspection tools that you may find useful.



Detailed Joint/Critical Joint Inspection


Perform a detailed joint inspection or critical joint inspection on the truss in addition to the Preliminary Truss Inspection outlined above.  Perform a minimum of one detailed joint/critical joint inspection on average per truss inspected.  Inspect both sides of the joint.  Items to check include:

  • Plate placement (plate mid-point location)
  • Member defects
  • Member gaps
  • Perimeter plate embedment
  • Plate rotation

As with the "preliminary inspection" record all of your inspection observations but instead of recording them on the truss or engineering drawing record them on the full scale joint detail locating the actual plate mid-point, member defects including flattened teeth, plate rotation, and tooth count if required and checking each items observed during the inspection off as you go and making note of any variances.  Once all detailed/critical joint inspections are complete record a summary of your findings on the TPI Inspection Formwork.