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Stephen Tashiro
02-11-2010, 12:33 AM
When a ribbed metal roofing panel reaches the bottom edge of the roof or the beginning of a piece of sheet metal that is being used to flash around something like a vent pipe, are the ends of the ribs left open "to breath" or is sealent used at the end to close them?

Ken Fitzgerald
02-11-2010, 12:35 AM
Stephen....around here I see them left open......the trouble arises when wasps go up under there and set up nests.

David G Baker
02-11-2010, 12:45 AM
Stephen,
There is a rubber like item designed by the manufacturer of the metal roof panel that matches the pattern of the panel that closes off the panel to keep critters out as well as stop air movement to keep moisture from forming on the bottom of the panel due to the temperature difference between the panel surface and the underside. The device is about 2 inches by the height of the ribs, and as wide as the panel.

Bill Rogers
02-11-2010, 8:39 AM
The items that David is referring to are called Closure Strips, but I suppose that you could call them gaskets. Typically there is an Inside Closure strip that goes on the bottom of the panel and an Outside Closure Strip that goes on top of the panel.

Stephen Tashiro
02-11-2010, 2:14 PM
I've read that one should not have aluminum in contact with steel roofing panels. I suppose that's why rubber or plastic is the preferred material to seal the ends. What about the places where you would ordinarily used flashing like where a panel would meet a parapet wall or around a chimney? Can you use aluminum roll flashing with something under it to keep it from being in direct contact with the steel?

There is a Bob Villa video of a contractor installing metal roofing panels. They install it around a vent pipe by using the existing flashing around the pipe. The merely rearrange it so the panel up-slope from the flashing overlaps the flashing and the panel down-slope fits under the flashing. It looks like the flashing is galvanized steel. Of course in the video, they have planned things so there is no rib that has to fit under the flashing. It made me wonder if things must always be planned that way.

Matt Meiser
02-11-2010, 2:26 PM
Small birds can even get in if left open.

Bill Rogers
02-11-2010, 2:48 PM
There are only so many standard roofing details. If you check the manufacturer's website you should find the roofing industry standard flashing details.
If you don't know the manufacturer and the profile (5-V crimp, standing seam, batten or etc.) then send me a picture of your metal roofing panels and I will find you the flashing details for your roof.

Stephen Tashiro
02-11-2010, 6:32 PM
I haven't ordered any roofing yet. The local Lowes can special order this panel http://www.abcmetalroofing.com/abcroofing/products_pbr.jsp, which is one that I like.

I'm as interested in understanding the methods and the reasoning behind the methods as actually doing any work. All I would be doing is putting in on a small storage building roof. Before I do that, I need the build-up the illusion that I know what I'm doing.

Ken Fitzgerald
02-11-2010, 6:43 PM
Stephen,

The reason you don't want dissimilar metals touching is electrolysis will set up between the two metals. The metals will end up corroding and disintegrating.

Bill Rogers
02-11-2010, 7:10 PM
Stephen,

Electrolysis is relatively easy to prevent. Just put a separation barrier between the two metals. The barrier could be 30 lb. felt, paint, caulking a bituninous primer or etc.

Bill

David Freed
02-11-2010, 8:06 PM
There is vented and unvented in both inner and outer closures. The company I work for sells aluminum faced bubble wrap to put under the metal. That is almost the only thing people order anymore because it works so well.

I deliver buildings and materials for one of the largest manufacturers in the country. They sell material to dealers in Mexico and Canada also. They have many types of stock trim and can make any type of special trim you might want. There may be a dealer near you. I can post their website if you are interested.

Stephen Tashiro
02-11-2010, 9:16 PM
I'd be interested in the website just to see the various types of trim.

Thanks to my advisors in this thread, I now know about closing the ribs on the down-slope side of a panel. On my storage room roof, there is a raised wall around the top and sides, so instead of overhanging, the roof has to be flashed where it meets this wall. I can see that someone who planned a roof well could plan it so the panels meet the side walls at a flat place on the panel, assuming we cut the panels on those edges. On the top edge, it seems to me that the ordinary L-shaped flashing job wouldn't work because of the ribs. I've seen ridge cap pieces of trim for metal roofs at Lowes. I don't really see how these fit over the ribs or even whether they are supposed to fit tightly over the panels. I've see "ridge vents" on ordinary roofs. May that's what this trim is.

David Freed
02-11-2010, 9:37 PM
I'd be interested in the website just to see the various types of trim.

I've seen ridge cap pieces of trim for metal roofs at Lowes. I don't really see how these fit over the ribs or even whether they are supposed to fit tightly over the panels. I've see "ridge vents" on ordinary roofs. May that's what this trim is.
That is where you would use the outer vented closures for a vented ridge cap. The ridge cap is screwed to the top of the ribs and the closures let it breathe.

http://www.graberpost.com/
Their website isn't very extensive, but they have booklets that show all kinds of trim. They would probably mail it if you ask.

David Freed
02-12-2010, 7:49 AM
I have never seen this before. My last reply won't show unless you click on More replies below current depth.. (http://www.sawmillcreek.org/showthread.php?p=1341948#post1341948) in the top box. :confused:

Bill Rogers
02-12-2010, 9:35 AM
Stephen,

The details that you need to look at are Roof to Wall (Headwall) Transition and a Roof to Sidewall Transition (with or without the use of a Z closure).
The Peterson Aluminum website has a drawing of a Roof to Wall transition (http://www.pac-clad.com/products/metal-roofing/redi-roof-batten) and it has installation videos.
If you can't find a Roof to Sidewall detail by doing a Google search then I might be able to send one.

Bill