Energy Star--Standing Seam Metal Roof


  #1  
Old 12-16-05, 07:52 AM
Torig
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Question Energy Star--Standing Seam Metal Roof

My husband and I are looking to replace our roof with standing seam--in red, the brighter the better!

We have found a couple places that list their metal roofs as Energy Star, while most do not. And of course we are getting conflicting info from folks as to whether that rating is necessary or not.

We understand the ES rating on the roof is an add'l coating which ups the "reflectability" of the roof. However, some are saying that unless you live waaaay south, or unless you want a white or cream colored roof, this is totally unnecessary.

We are in Ohio, and we want a bright red roof. Soooo--any tho'ts on whether we need to go w/ an ES rated roof or not?

Many, MANY thanks!
Tori
 
  #2  
Old 12-16-05, 12:35 PM
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Bright red fades in the sun

Hi Torig,

While bright red is a beautiful color, the pigment that is used to get the bright red color is unstable under UV exposure. I have seen a number of bright red roofs become pink and even white in as little as 15 years of exposure. When I was discussing this problem with a chemist from a paint company, he told me that unfortunately, no-one has yet been able to get a UV stable bright red pigment. Other shades of red, which use a different mix of pigments, will last longer.

As for the Energy Star label, the reflectivity comes from the choice of pigments, resins and substrates which result in more reflectance of solar energy. If your attic is well vented (interior attic temperature is not much hotter than the outside air), then you may not see much benefit. If your attic gets very hot in summer, then using the energy star products should lower somewhat the heat absorbed by your roof. As well, most of the materials used to achieve the energy star label will be more stable under sun exposure. To decide if the Energy Star feature is important to you, you really need to look at your roof (and attic, insulation, ventilation, etc.) as a system, with the roof covering being only one part of the system.
 
  #3  
Old 12-16-05, 05:27 PM
Torig
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Thanks--'nother question!

Thank you so much! But here's more info--we have NO attic. Nada. Zip. None. There are some sorts of vents in the roof--but no attic. And yes, it gets very hot on the second floor.

The roof is now shingled, and they are not in too bad a shape; the contractors are going to (as I understand it) insulate OVER the shingles--build some sort of grid thing for the standing seam, and insulate between that and the shingles. (Does that make sense? Maybe my dh should be on here instead of me ) They did not feel it necessary to tear all the shingles off first.

Re: the bright red: I wanted it because I have seen OLD standing seam red roofs in the south that are still gorgeous after 30 or more years! Is that because of the "south", no harsh winters, etc. or --like so many other things--has quality worsened over time?

I also tho't we had to re-paint the roof every 12-15 yrs or so anyway--not true? A cream color would "go" with the house, but we're in a kind of wooded area, and all I can see is that it would get filthy within just a few weeks (ugh) and show dirt just like a white carpet. Am I being too Female about this???

Obviously we want the best roof we can afford. It is also quite--er, wintery, here now. Apparently we can get the NON ES roofing in a week or so; the ES roof will take about 4 weeks. We are QUITE willing to wait longer if the ES rated panels will be worth it. Sooo, did I give you enuf more info to help me out even more?

Thanks for any other input--I truly do appreciate it.

Tori
 
  #4  
Old 12-21-05, 01:39 PM
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Some opinions

I suspect that the 30-year old bright red roofs have been repainted. Pretty much every bright red roof in our area (Montreal, Canada) that I have seen has been repainted. Some of the metal roofs we have in our area are over 100 years old, so if you do maintenance on the metal, it will certainly last. On the other hand, if you let it go... rust will sooner or later show up.

Given that you have no attic, the problem changes somewhat. The usual method of installation of vertical standing seam panels is to attach them to horizontal furrings, which provide the support for the panels and also create an air space. If the air cannot move by convection, that air space is not ventilation. So to get rid of heat, you would want to install first vertical furring strips, then horizontal ones, then the metal panels. The vertical strips will create vertical air channels, which if you provide the appropriate entry at the soffit and appropriate exit at the ridge, will give you some basic ventilation. By using the energy star products, you may reduce your heat transfer from 10-20% over non-energy star products, and by providing the ventilation space, you should be able to dissipate at least 50% of the heat that gets past the metal.

You could go an extra step and consider improving your insulation in your current roof, and that will further reduce the amount of heat transferred from the roof to the house.

As for color choices - that's very personal. If your roof is relatively low slope and there are many trees around, you may end up with tannin stains, but the leaves would have to stay in one spot for a while and be wet. I have a light colored aluminum roof on my house, and I do not have any kind of dirt or staining showing up. As for whether you have to repaint, that depends on the quality of paint that is used. If your supplier is using PVDF paints (brand names Kynar, Hynar, etc.), then you should have the painted surface last at least 20-25 years. Cheaper paints based on polyester or acrylic resins may start to discolor in as little as ten years.

As a practicing roofer, even though many companies say you can go over an existing shingle roof, I don't like to do that. Three reasons: I want to see if there is any damage to the deck, and repair it before installing the new roofing. Two, it reduced the weight on the roof by getting rid of the old stuff. Three, many water-proofing methods, like the use of ice-and-water shield membrane, require adhering the membrane to the (clean) deck. To me, putting a new roof over an old one is like putting on clean clothes over dirty ones and not taking a shower. Doesn't work for me. Of course, it is more expensive to strip, but most (OK, almost all) of my customers want the quality over saving a few bucks.

Personally, I think you should be spending more time looking for a good and qualified roofer, since at least 80% of the quality of the roof will come from the installation. But that's already another story...
 
 

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