Metal roof transition?
#1
08-22-08, 02:03 PM
Metal roof transition?
In designing my future house, the roof has a transition from one pitch to another- 12/12 upper to 4/12 lower. How does one seal that transition? I'm afraid of wind pushing water up the 4/12, and getting underneath the upper part. Since the roofing is 3 dimensional (ribs) I don't see how to flash it in an attractive manner. Any suggestions?
#2
08-23-08, 08:53 PM
Group Moderator
No one has taken a stab at this one yet, so I'll stick my neck out. I don't work on metal roofs every day. 
You'll need a custom bent flashing that will go over the 4:12 roof by at least 6" (providing 2" of drop), and will go under the 12:12 roof by about 4". You'd use foam closure on top of the 4:12 roof before laying down the flashing. Once the flashing is down, you'd use foam closure on the upper part of the flashing before laying down the panels on the 12:12 roof.
***They may also make a metal closure flashing that is made just for such a situation, that would fit over the humps in your roof panels, and be more attractive than a flat flashing that only hits the high points. (I would think your roofing supplier would be able to get you what you needed)
Being in Florida and SC, it's possible that your local codes would require a water shield membrane under the entire roof.
You'll need a custom bent flashing that will go over the 4:12 roof by at least 6" (providing 2" of drop), and will go under the 12:12 roof by about 4". You'd use foam closure on top of the 4:12 roof before laying down the flashing. Once the flashing is down, you'd use foam closure on the upper part of the flashing before laying down the panels on the 12:12 roof.
***They may also make a metal closure flashing that is made just for such a situation, that would fit over the humps in your roof panels, and be more attractive than a flat flashing that only hits the high points. (I would think your roofing supplier would be able to get you what you needed)
Being in Florida and SC, it's possible that your local codes would require a water shield membrane under the entire roof.
#3
08-29-08, 10:59 AM
What are the roofing materials your going to use on each area?
Is the 4/12 going to be a membrane roof or the same as the 12/12?
If both roofs are of the same material and im guessing its a standing seam panel system than it would be all ice and water shield prior to installing the panels and then special bent piece would be installed at the transition and the panels will hook onto that piece.
Sort of like this detail but with a different pitch
:http://technicaldatabase.fsbp.com/te...hx?fileId=5115
Is the 4/12 going to be a membrane roof or the same as the 12/12?
If both roofs are of the same material and im guessing its a standing seam panel system than it would be all ice and water shield prior to installing the panels and then special bent piece would be installed at the transition and the panels will hook onto that piece.
Sort of like this detail but with a different pitch
:http://technicaldatabase.fsbp.com/te...hx?fileId=5115
#4
08-29-08, 02:46 PM
If I'm looking at it right, that is a valley seam? I will have valleys to deal with, too, but I'm talking about a transition in roof pitch only. The roofing will be some kind of metal- maybe 5v; maybe standing seam. Both the upper and lower roof will be the same material.
#5
08-29-08, 03:07 PM
I know its a valley detail but I couldn't find the exact detail right off hand.
Its going to be very similar to the valley minus the v in the center and it would be bent at the the pitch/angle you need it.
But the concept is the same.
Its going to be very similar to the valley minus the v in the center and it would be bent at the the pitch/angle you need it.
But the concept is the same.
