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Flat Roof Damage

4300 Views 6 Replies 7 Participants Last post by  Homeinspector
How do you test a flat roof for uplift? "Wind damage to a flat roof"
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Good Question, I am thinking your employer woul dhave some guidelines. All the wind damage claims I have been involved with were obvious and sections of the roofs were blown off. There was nothing to test, so I can't be of much help.
wind up lift

steel deck, wood deck or concrete?
I have never seen anyone test for wind uplift on a roof before, but i know that it is done by companies such as Factory Mutual in their laboratories. Uplift is measured by pounds per square foot. The amount of wind uplift on your roof depends on a lot of things such as your building height, the terrain around it, parapet walls, decking, etc. FM has tested in their labs wind uplift at different levels and developed roofing systems for that particular wind level. So for example FM has roof classifications such as I-60, I-90 and I-120. Each one is at a different wind uplift rating and each system has to be installed with certain decking, insulation thickness, amount of fgasteners per board, etc. It gets a little complicated but if you know what type of roofing system you have and what type of deck you can figure out a round about number that your roof system should be able to handle. As for a tool to test on the roof i have never seen one other than a fastener pull test tool. (doesn't mean there isn't one out there LOL) Sorry for the long explanation.
you can't test for wind uplift unless you have the proper equipment and have been certified? You can read the manuals to determine the amount of fasteners to use to achieve a certain uplift resistance.
Ets80 is correct. Most field testing pre-damage is tested by the use of a pressurized wind uplift chamber such as a bell chamber. Insofar as wind uplift post event, when the roof is blown into a pile in the NE corner, it can be easily discerned there is an issue. However, I have seen roofs lift and set with very minimal noticeable damage at first glance. I would recommend retaining a qualified forensics firm who deals with this issue on a regular basis.
Good advice. I concur.
Ets80 is correct. Most field testing pre-damage is tested by the use of a pressurized wind uplift chamber such as a bell chamber. Insofar as wind uplift post event, when the roof is blown into a pile in the NE corner, it can be easily discerned there is an issue. However, I have seen roofs lift and set with very minimal noticeable damage at first glance. I would recommend retaining a qualified forensics firm who deals with this issue on a regular basis.
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