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Water ponding

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Roy Duff
1/30/2016
I recently had a metal roof installed on an older flat roof house. The 43' R panel were attached to purlins which were attached with lag screws through the existing tar roof and plywood underlay, the purlins were graduated creating about 1 foot rise in the 43' length. Butyl tape was applied to the panels. My concern is a small area of ponding created by a metal chimney pipe which had a diameter wide enough to block between two ridges on the paneling. The boot over the bottom of the chimney appears to have been properly installed. My concern is the area about 2'x2' where the water is blocked.
Todd Miller
Isaiah Industries, Inc.
1/31/2016
Do you know the minimum roof pitch required by the manufacturer for the R Panel you installed? I suspect this is far below it. The butyl will help but I suspect you will fight problems with this installation. I am sorry. You could add additional sealant to the panel overlaps where the water is ponding but basically you're trying to create an aquarium of painted metal. I wish I could be more optimistic. Sorry.
Dick Bus
1/31/2016
ponding on any roof system is a bad thing. that being said there is a way to prevent the ponding. e-mail me at [email protected] and I will have a detail e-mailed to you that will solve the problem. how far from the ridge is the pipe penetration?

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