%Cause
47.6Poor workmanship
2.6Roof traffic
16.7Poor design
7.8Trapped moisture
8.0Materials
8.4Age & weathering
Potential leak locations include the following:
■ Flashing
■ Drains
■ Penetrations
■ Seams
■ Blisters
27.3.3.2 Safety precautions
■ Recommend a minimum of two people on a roof, preferably three or more.
■ Inspect the underside of the roof for structural integrity prior to walking on it.
■ Avoid stepping on blisters that are common on built up bitumen and gravel roofs.
■ Have a cell phone or radio available in case of emergency.
■ Inform local police and plant security prior to doing nighttime roof survey.
88 Publ. No. T559597 Rev. a554 – ENGLISH (EN) – September 27, 2011
27 – Introduction to building thermography