Corrugated metal siding and color
Hi All,
I’ve always been planning to do the majority of my siding in corrugated metal(with some wood accents). It’s durable, I like the look, no maintenance, its a rain screen, and cheaper than wood options I like.
Galvalum(silver) has always been my go-to but I recently have been tempted by darker colors, even black(which looks more like a dark dark navy)
I am wondering if it will be too hot in the summer? For what it’s worth the manufacturer still calls even the black a “cool” color, meaning its designed not to absorb as much heat as a traditional darker color.
I live in the coastal PNW, it really does not get that hot here. Sometimes during a heat wave, it might reach into the 90’s but it’s rare.
Should I take color into consideration at all?
Thanks
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The only caution i can give you is to read the fine print. I have seen WHITE metal that WAS NOT considered a " cool color".
More to it than just the color of the coil its made from.
All of the Kynar paint from this particular manufacturer claims to be "cool"
Hi Joe.
Because black metal siding gets hot, it may still need to be installed over a rainscreen gap to protect the WRB from the heat. It also has the potential to create ice dam at the eaves. That's all according to this FHB article by Mike Maines: Choosing Black Siding. Of course, climate and solar orientation are factors to consider as well.
Ice dams are not much of a concern where I live, rarely snows enough. Do you know if Commercial Tyvek has a heat rating I can look for to determine if it may be a problem?
The tyvek users manual says not to exceed 175*F and that at 220*F Tyvek will start to deform. Those are HOT temperatures. The highest attic temperatures I’m aware of are up around 140*F which makes me think you’ll be pretty safe.
Note that a rainscreen gap with both top and bottom venting will provide convection cooling of the back of the siding. This will greatly reduce the peak temperatures that will be seen by anything on the inside of the gap.
Bill
Thanks Bill,
I was planning to use the metal vertically, allowing it to act as a rain screen without adding furring strips. That means the metal will be in contact with the Tyvek(another good reason to add a little foam, I suppose). I'm not quite sure how id detail the top and bottom to give enough breathability to create convection. Thanks for the temperature info. It seems like it'd be hard to reach these temps in the PNW coastal region.
Joe,
I've opened up a few south facing walls in the PNW that where clad in corrugated galvalum and never found any damage caused by heat.
The profile of the siding makes it a rain-screen under our code without furring. We typically install it on a perforated metal drip-flashing at the base. It doesn't perform as well as rain-screens with furring, but it is better than not having one.
You can get something like this bent up for the top and go with perf trim on the bottom:
https://www.ascbp.com/wp-content/uploads/ASC-Building-Products-Vented-Peak-Flashing-e1559672024777.jpg
I'm using charcoal gray. It does get too hot to work with when laid out in the sun, but once on the wall it's tolerable, so probably not hot enough to affect the foam under the rainscreen.
Joel,
Looks good!
Agreed. Nice work!
Joel, Looks nice.
I did corrugated siding on my last project and had pretty good luck teaching myself how to detail it properly. That said, I'm sure there are some tricks that would be handy. Do you know of any resources for metal siding details on the web?
I wish I could say I found any usable resources for horizontal siding installation. I had previous experience with vertical siding so that helped with the basics. I found only one manufacturer (Ideal) who sold a complete line of trim that was sized for their panel, and even debated buying a sheetmetal brake to make it all (glad I didn't - there's a lot of trim used). All of the manufacturers seem to give details for basic roof and pole barn applications.
That being said, I did learn a few things and it would probably be best if I tried to put it all down in a logical sequence along with photos I took along the way. Until I get around to that, if there's anything specific I might help with, just ask.
A lot of building codes now mandate having a layer of exterior insulation attached to the sheathing. If you need to have one you could add a layer of Roxul Comfortboard mineral wool insulation over your building wrap before adding the strapping. That would help mitigate the heat from the metal siding.