Ops Talk Magazine Fall 2012

Page 38

Roof evaluations: are they important? By Zen Szewczyk, vice-president IRC Building Sciences Group Inc.

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Ops Talk • Fall 2012

You would think after performing thousands of roof condition evaluation reports and preparing the same amount of roof design drawings and specifications, one would rarely come across a situation that presents a unique problem. Well, after over 25 years in business, it happened. Our firm was called in by a school district to evaluate the extent of deterioration of the roof assembly on a building that was over 30 years old. The roof was the original four-ply asphalt built-up roof (BUR). The owner was not experiencing many leaks; however, due to the age of the roof, the owner thought it might be prudent to perform some preventive maintenance to extend the life of the roof indefinitely – or even retrofit the roof with additional insulation, as they didn’t think they had very good thermal resistance. We arrived on site to find the roof completely under water, so our initial investigation was limited to some wading around and interior investigation. One thing we noted on the roof was relatively few roof drains. The existing deck varied from area to area, and consisted of poured-in-place concrete, metal roof deck, wood roof deck, and concrete slab. The underside was plastered ceiling. There was little water staining, and it was limited to around openings. Sometime later, when the roof surface was dry, we returned to complete our evaluation (Photo 1). Infrared scans, core-cuts and probes each indicated total moisture saturation


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