Metal Roof Penetrations: “Pipe” Dreams Or Nightmares?
By Erno Ovari, Copper Exclusive
It has been said that the first rule of metal roofing is to never penetrate your roof. This is my rule, too. The only reason why I don’t like penetrations on my metal roofs is that they are just plain ugly. Don’t get me wrong, I believe first and foremost in waterproofing everything I do—permanently—without soldering or sealants, but cosmetics wins out, too. Most metal roofers would agree that a no penetration roof is a beautiful roof. I would add that a no penetration roof is a beautiful roof-- except when you make a penetration as an adornment. Let me explain:
We live in the real world, and if you’re remodeling an historic residence, for example, it’s not always possible to relocate the HVAC pipes protruding from the roof to a more practical location. We all know this. What we don’t all know, is that you don’t have to make a bad situation worse by applying glue and screwing through your metal roof in the act of attaching a rubber boot. This not only would penetrate my roof with the necessary screws, it also would need caulk or other sealants which in turn would disappear in a very short time frame and would devalue my work from the onset. I know rubber boots are a popular choice and they certainly have their place, but for fine work, there is a better option. For me, a rubber boot ensures that I would have to come back for regular maintenance. The whole point for both me and the customer is for me to NEVER have to come back for mess clean up.
A personal example comes to mind. As a board certified sheet metal roofer for historical buildings in Europe, I was called in to do a repair job on a castle with a 250 year old roof. The reason for the repair was that during a storm, a tree had fallen causing some damage. When I got up there, every single detail (except for the tree damaged portion) including the many roof penetrations was still intact and functional. If I had come up suggesting a “rubber revolution” solution, I would have lost my license AND my reputation. Ok, that was a castle, but the techniques on any quality building should be the same. In day-to-day work here in the U.S., what kind of answers are we coming up with for our clients?
Some of us could try to solder a roof penetration together. This technique would work on a copper, zinc, or stainless steel roof but not for painted steel roofs which are much more common because of cost. Soldering a roof penetration certainly calls for knowledge. Unfortunately, you can’t resort only to solder. To make a soldered penetration properly, you can’t avoid first seaming the pipe part of the flashing into the roof from the back side of the panel. Solder on its own would be short-lived. The incessant expansion and contraction of the metal would make the solder joint a fleeting remedy. I see copious use of soldering on projects from valleys to penetrations where the difficulty level is higher and people don’t know what else to do. Seaming is the one and only option to create a lasting effect.
I say, take your lemons and make lemonade! So you shouldn’t solder, glue, or use screws to solve your pipe nightmares. What of it? Make your pipes a beautiful feature! You care about quality, so make them watertight and make them last forever. I had this column in mind when I made the roof pictured in the following Power Point presentation. In it, you will see three different ways to accomplish this technique. Of course there are many more than three ways of doing this, and construction will depend on location and structure, but it is a good start for those of you interested in making this technique yours.
Yes, I realize this solution is more time intensive and is the Mercedes version, but honestly, who doesn’t want to drive a Mercedes?
The following link shows how to handle pipe penetrations in metal roofs: www.copperexclusive.com/shopping/ProductImages/roof-penetration.pps (PowerPoint file. A free PowerPoint viewer can be downloaded at www.microsoft.com.)
Erno Ovari of Copper Exclusive began his career in metal craft in 1985. He has experience in Germany, Austria, Hungary and Switzerland as well as 11 years of intensive education in this trade. He has achieved the degree of “Meisterbrief”, the highest contractor certification in Europe. To contact Erno, call (801) 227-4110 or email to erno@copperexclusive.com.
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