penetration flashing at new construction ?

Alan Batson
registered architect
12/6/2006
Hi, I am an architect having a Galvalume standing seam metal roof installed on a new home I am building for myself. Would you please give me your opinion - I am finding scant information on this topic. Should the penetrations be made before the roofing is installed or after ? My contractor insisted my solar subcontractor make his penetration before the roof went on, and the plumbers made their's too. But the 10" round fireplace flues - I'm being told it's best to make them after the roof has been installed. This simply does not make sense to me. My specs call for a 10 year written guarantee, but that's only as good if the installer is around in 10 years. Architectural Graphic Standards and other references I have are mute on the subject. What do you think. Shoud I insist there be chimney collars in place prior to laying the standing seam pan on top of it ? Do you know a source for this sort of detaling ? Thank you so much. Please feel free to look at pictures of the house on my website placecraft.com. Alan Batson, architect
Todd Miller
Classic Products, Inc.
12/7/2006
All penetrations should be in place before the roof is installed. Chimney collars will usually come down over the roofing though. Have you chosen a quality product from a quality manufacturer and do you have a quality installer? Let me know how I can help.
Guest User
12/11/2006
Hey Todd, thanks for your response. They are doing things in the right order, according to what you say. The material looks fine - from Coastal Metal, which has a good rep. The installation looks awesome so far, especially since they seem to be getting the penetrations correct. I love the little machine they send down to fold the seams, and how it reverses itself to climb back up. The whole reason I went with standing seam is we're putting a huge photovoltaic system on it using s5! clips, etc. That and the Galvalume is energy star rated. It's weired how it's so reflective that it almost disappears into the sky in photos. I'm really happy too at how modern it looks, which is hard to do on a gabled house.
Todd Miller
Classic Products, Inc.
12/11/2006
Glad to hear all of this.
Alan Batson
registered architect
12/16/2006
Thanks Someone asked me a question though and I don't know the answer. How do I know it's Galvalume they installed and not galvanized steel ? I couldn't find where anyone else asked that . . . .
Allan Reid
Dura-Loc Roofing Systems, Inc.
12/18/2006
Visibly, the Galvalume metalic coating has very small spangles on the surface and looks a little duller with the aluminum in the coating than Galvanized which has much larger spangles from the zinc.
Alan Batson
registered architect
3/30/2007
Hi People, I am so frustrated I could burst. Help please ! I've been unclear on the proper way for a metal chimeny to penetrate a new metal roof. Now the fireplace people came and apparently with the roofer's knowledge/blessing installed the three gas fireplace chimneys. First, they did not get them in a straight line - for no reason in the attic, which just shows their very poor standards of workmanship. (see pic) Worse though, they used rubber boots which are siliconed and screwed down on top of the roofing, seams everything. I can't believe this is how this should have been done in brand new construction. From inside the attic, the holes in the sheathing and roofing are so bad, the gaskets barely cover and I have daylight holes through which I could stick my finger, but for the dab of silicone there. (see pic). How is a metal chimney supposed to penetrate a standing seams roof ? The pipes are so wide they can not sit inside the pans inbetween seams. Also in pattern of roof structure and standing seams, the preserving the roof structure wins. So I get that battle is lost. At this point we're holding back ALL the money paid for the roof and all money paid for the fireplace from our contractor's next draw request. We're in for $36,000 for the roof and $17,000 for the fireplaces Certainly there is an established and respectable way to have a metal flue penetrate a metal roof !?
Alan Batson
registered architect
3/30/2007
heres an inside shot
Todd Miller
Classic Products, Inc.
4/1/2007
I am not familiar with the flexible flashing that they used. However, I have seen similar things in the past. I assume those collars will be pulled down over the flexible boot? Is the flexible flashing rated to withstand the heat from the chimneys? Have you contacted the manufacturer of your roofing for their input? Things may not be as out of order as you think though I would definitely contact the roofing manufacturer.
Alan Batson
registered architect
4/3/2007
Hi Todd, The manufacturer of the chimney sleeve is Selkirk. http://www.selkirkinc.com/index.html They make an alternate meatl system which I am attaching here (a pdf.) The Tech person at Selkirk was very helpful attitude wise, but she was stumped about apllying this to a standing seam roof - when it comes to attaching the sides. There is space for heat dissipation between the rubber and the chimney. I too said the collars should be pulled down. I need to contact the roofing manufacturer - yes. This is what I get for letting my g.c. let the chimney people mess with roof penetrations!
Todd Miller
Classic Products, Inc.
4/7/2007
Let me know if you have more questions.
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