Condensation - Pre-Engineered Steel Building - LONG!!

Daniel Tarr
1/21/2006
I am involved with a Pre-Engineered Steel Building that is approximately 75' x 125' with a 24' Eave Height (It is a Gymnasium). The roof pitch is 1:12. The plans called for a 2" Standing Seam Metal Roof Panel to be placed over 2" Rigid Insulation that was to be over a 1.5" Acoustical Metal Deck. The ridge was to have been continuously vented. The Contractor that constructed this building did not install the Continuously Vented Ridge. Furthermore, the Contractor did not tape or seal any of the joints in the Rigid Insulation. The contractor placed a piece of "Finish Metal" at the peak, leaving a dead space between the "Finish Metal" and the Ridge Cap. On cold mornings, around 8:00 - 9:00 am, condensation begins to form at the peak of the roof, on the "Finish Metal". The contractor has told me that if the building was constructed as designed, all of my hot air would leave the building and my heating bill would be extremely high. (Evidently he was not worried about my cooling bill in the summer!) His solution to the problem was to stuff Batt Insulation 6" down the ridges in Acoustical Metal Deck Panels, then he placed unfaced batt insulation between the "Finish Metal" and the ridge cap. Although we have had some cold mornings, the condensation has seemed to stop. Was this a proper fix to the problem? Was the original design correct? Shouldn't there be some "warm side" ventilation? Won't the warm air still permeate through the Acoustical Metal Panels, through the untaped rigid insulation, and condensate between the Standing Seam and the Rigid Insulation? Thank you in advance for any information that you may have on this issue!
Allan Reid
Dura-Loc Roofing Systems, Inc.
1/23/2006
It depends on the type of ridgid insulation as to open or closed cell and on the tape etc but it does not sound like you have an interior air barrier in the system and were relying on the tape, then the warm moist air is going up through and condensating. It is time to bring in a expert consultant.
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