2300 KASCH PARK RD 2020-12-31 - Laserfiche WebLink

• • Mr. Larry Daubenmire October 09, 2018 Cge 6 OBSERVATIONS Larry Daubenmire (with Community Transit) accompanied us during our site observation. Also, another Community Transit staff member was there and provided us with access to top of roof using a man-lift. Our observations of the underside of the shed roof consisted of a walk-around at ground level. The underside of the roof was completely open, allowing an unobstructed view of the steel roof decking and supporting structural members. The underside of the decking, supporting members and.their connections were all painted and appeared to be in good condition with no signs of deterioration (Photo 2). On the top side of the roof, the galvanized steel decking is exposed and exhibits a significant amount of corrosion across the entire surface (Photos 3 &4). Above the support framing below, nearly all of the screw heads showed signs of corrosion (Photo 5). The roof decking slopes down to the south to a continuous gutter. At this gutter, a small amount of standing water was observed. Along the bottom of the gutter and the sides near the base, an extensive amount of corrosion was observed (Photo 6). CONCLUSIONS AND RECOMMENDATIONS Based on our observations from atop the roof assembly, the existing steel decking exhibited a minor amount of corrosion and appeared to be in fair condition. In our opinion, it is unlikely that the deck's structural capacity has diminished; however, if left untreated, the condition will worsen and the structural integrity will be impaired. Due to the condition of the existing steel deck, we recommend that corrective remedies be completed within the next 24 months. One corrective option would be to replace the entire steel decking assembly with new steel decking. A second option would be to keep the existing steel decking in place and to install a new roof overlay directly atop. The new roof overlay would need to serve as a water-tight membrane, protecting the existing steel deck from any moisture and further corrosion. Based on the February 14, 2017 evaluation report from Wetherholt and Associates, it is our understanding that this second option is preferred. The new roof overlay would need to be light-weight, the added weight of the assembly no more than 1.3 pounds per square foot. Current building codes for existing buildings limit gravity load increases to 5% and lateral load increases to 10% on structural elements. For loads in excess of either of these values, the building code requires an analysis of all building elements affected by the increased loading. Limiting the new roof overlay weight to a maximum of 1.3 pounds per square foot would keep the load increases to within the allowable 5% / 10%threshold, and an analysis of the building elements would not be required.