6.3. SR 08-13-2012 - Laserfiche WebLink

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Our investigation on April 12, 2012 was the first time we observed structural members within the facility since February 2009. Over 20 areas were investigated during the April 2012 site visit. Many of the areas previously exposed during the February 2009 investigation were reviewed again in addition to newly exposed members. The amount of corrosion discovered varied from little to no corrosion to scaling steel. For the purpose of this report the amount of corrosion will be defined as the following forms: No Rust Painted base metal with no rust. These areas were used as control specimens. Surface Rust that is removed easily with wire brush without pitting or scaling and no loss of useable thickness. Pitting Surface rust with some pitting of base metal but no Scaling and no loss of useable thickness. Scaling Base metal has pack rust and presumably a loss of useable thickness. In order to access the steel structure the finishes and paint had to be removed at that area. These materials should be replaced by you. Once the finishes were removed the steel could be visually inspected for corrosion, the paint or rust removed with a sire brush or emery wheel, and the useable thickness of the steel determined by American Engineering and Testing. Observations: Throughout the roof structure areas of corrosion ranging from surface rust to scaling were noted on the roof purlins, bracing members, and bents. The majority of the areas investigated were corroded with surface rust that should not be a major concern at this time. A few areas displayed some pitting and only a few areas were scaling. Although only a few areas had scaling this is an increase in corrosion since the February 2009 investigation. This suggests that the conditions that promote corrosion within the building still exist. Typically areas of corroded steel were made evident by a discoloration or water marking of finishes and bare steel. Because these water marks did not travel long distances and appeared to dry without significant dripping we believe the presence of water is due to condensation and not a leaking roof.