The 1:12 pitch will require a mechanically seamed standing seam. The transition flashing needs to go under the upper roof and out over the lower roof. Pencil ribs are small ribs sometimes formed into the flat areas of the panels. They can be rounded or squared off and even fairly wide. Striations refer more just to undulations formed into the flats of the panels. these are done to provide strength and minimize and ripples in the panels. It would be best if the roof on both pitches is the same. I would suggest a seam height of no less than 1.25" and probably more. I assume the lower pitch roof is downhill of the steeper roof? How long are the rafter lengths?
Todd Miller
2016-04-11 09:41:05.000000
Hi Nathan,
Thanks for your question about metal roofing.
The slope change transition detail that you are asking about can be challenging when the change is slope is not very great, like 2:12 to 1:12.
With this great of change in slope that you have, the detail is relatively easy for all common metal roof profiles. The decisions about panel depth, striation and pencil ribs should be based on other reasons, like load capacity and aesthetics rather than slope change detail reasons.
Regards,
David
David Stermer
2016-04-11 09:46:41.000000
what is your advice on transition from 7/12 pitch to 1/12 standing seam installation. Questions: Define pencil ribs, striations, flat panel. How tall should the finished seam be?