Technical audits and expert inspections · Lesson 2 of 4

Technical audits and expert inspections: materials, standards and design constraints

The layers of criteria, why inspection intervals differ by product and warranty, what infrared and electrical methods cover, how to cite a standard by its scope, and the AFS limits a shop order is checked against.

You will be able to: Name the layers of criteria an audit compares against, compare published inspection intervals and survey methods, say what a standard's scope does and does not cover, and read AFS's limits and nominal thicknesses.

11 min · 11 slides · 8 questions

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Slide 1 of 11

Criteria come in layers

Criteria come in layers: the contract documents and submittals, the owner's requirements, the manufacturer's instructions and warranty, the adopted code, and, for AFS parts, AFS's published limits.

As practice advice, when two layers disagree, ask the specifier in writing rather than choosing one yourself.

Sources

UFC 3-110-03 Roofing (1 May 2012, Change 5, 12 June 2020): sections 7-3, 7-6 and Appendix E - U.S. Department of Defense (USACE, NAVFAC, AFCEC), published by WBDG
NIBS Guideline 3-2012: Building Enclosure Commissioning Process (BECx), final 25 April 2012 - National Institute of Building Sciences, published by WBDG
AFS fabrication limits - materials, thicknesses, bend rules and sizes the shop can make - Architectural Flashing Supply

Videos for this lesson

What this video shows: An equipment maker explains how electronic leak detection completes a circuit through trapped water to find a breach in a roofing membrane, and says infrared and capacitance locate moisture but typically cannot pinpoint the source. A manufacturer's own explanation, for membrane roofs.

Video: Forensic Electronic Leak Detection (ELD) Testing for Existing Roofs with Active Leaks by Detec Systems, on YouTube. Chosen from the video's published description.

Glossary

Submittal: A shop drawing, sample or product data package sent for review before work is made or installed. UFC says to require submittals to verify quality in the details and components.
Infrared thermography: A nondestructive survey that images heat to find wet roof areas. UFC says it surveys 100 percent of the roof surface and supplements, but never replaces, a visual inspection.
Core sample: A small cut-out of a roof taken to test it. UFC says to confirm an anomaly found by a nondestructive method with a core sample.
Girth: The total flat width of a flashing piece before it is bent. AFS's maximum girth, hems included, is 48 in off a 48 in sheet.
Nominal thickness: The stated thickness of a sheet metal gauge, for example 24 ga galvanized steel at 0.0276 in in AFS's register. The allowed tolerance comes from the governing material standard.