Pro-Rib barn steel question

[maradcliff]

I am using that Pro-Rib steel on a shed. I have used much of this stuff and never had a problem. I did the roof on the shed and found myself short one full sheet. However I had two half sheets left from another project, (cut the full length) and they were long enough. Weather was getting bad so I just overlapped the ribs and screwed them on the roof. For some reason, as soon as it rained, I had a leak. WHY? I have the ribs overlapping just like a full sheet, except these do not have that one special edge that they put on one side of every sheet. Yet, the ribs are fully overlapped and it was not even raining hard. There are no holes, cracks, tears, or misplaced screws. How the heck can the water jump over the rib? This makes no sense....

I thought Id see if anyone has had this problem and why.

Mark

[dpb]

...

Not specifically w/ the particular product, but...

What's pitch on this particular roof? I'd guess one of three possibilities--If the pitch is low you had a pooling problem where didn't shed quickly enough and w/o the sealing lip it did run over the edge. Alternatively, it could be the leak is actually somewhere on the upper end and is simply running down that seam to get through or there is simply enough capillary action w/o the seal to show up as the leak. Would have to see, I think, to have any better idea in a specific case such as this. I'd bet a closer inspection will reveal the problem/mechanism when you get a chance after the rains...