Have you checked out Decra stone coated steel shingles? I'm looking into them myself but have not yet determined if they qualify as a cool roof...
Guest User
2007-07-16 01:36:39.000000
I have some research to share on this issue of the green,cool, metal shake. The info was obscured by the fact no website I studied had 2009 Title 24 compliance data. California Title 24 is a useful shortcut to getting what I (and probably lots of other specifiers ) want- see page 63 of Metal Roofing Aug/Sept 2007.
So, I went on a plant tour of one local manufacturer and then visited a distributor - "RAM" (Jon Wilson).He answered all my arcane technical and installation questions,including one I had posed on this Forum that produced no answer. The requirements are:
1.Stone coated
2.Shake appearance
3.Cool roof with 25+% reflectivity
4.Self venting without battens.Yes, NO battens!
Number 4 is the problem! Title 24 'requires' a 3/4" vent space between the back of the panel and the roof deck. He had one product that had this feature - "SteelRock" www.steeelrockroof.com -linked below
http://tinyurl.com/3b37nn
Like many other manufacturers SteelRock are planning to change their rock grades to improve the TSR also. No, the 3/4" vent space is not mentioned on their website but I have a sample in my office and it measures 3/4"!
This leaves the questions:
1.Why isn't this being promoted to specifiers now?
2.Why aren't other manufacturers increasing the depth of their ribs to 3/4" or better? "Save the trees!"
The ability to meet Title 24 without the expense,penetrations and delay of battens/counterbattens is a valuable $ & green advantage and it costs the manufacturer very little.One die is only $300,000 +_ and these are routinely renewed anyway.
I would be very pleased to hear of anything anyone else can add to this subject if you email me: solarshading(at)mindspring.com
BTW the underlayment I was thinking of specifying is KoolBlue, linked below
http://tinyurl.com/3ykfs3
Thanks to the Forum for your comments.
Guest User
2007-08-10 17:39:30.000000
Tony, you have done some great research. You know your stuff.
I am not aware of Title 24 requiring a 3/4" airgap above the sheathing. I think it may require it somewhere in the roof system though which could be beneath the sheathing.
Please correct me if I am wrong.
I am not sure what questions you have. Please let me know.
Todd Miller
2007-08-10 21:29:08.000000
I am not aware of steelrockroofs. It looks to me like their products are manufactured by Decra.
Todd Miller
2008-09-15 21:34:33.000000
If you go the the "manufacturers" page of this web site (look in the banner at the top of the page), you will see a chart that lists several MRA members that produce the product you are looking for.
Ken Buchinger
2007-07-16 09:45:21.000000
Dura-Lok is a good company and an MRA member. Metro is an MRA member as well. You can e-mail them and I'm sure they would be happy to provide you with the info you are looking for.
Ken Buchinger
2007-07-17 10:10:16.000000
Need some guidance from someone with excellent product knowledge to find a stone coated metal shake that qualify as a cool roof.
There are plenty of stone coated metal shakes although some like Custom-Bilt's, Armor Star are not available in California(why?). The difficulty is getting one that has 25+% reflectivity to qualify as "Cool". Why have a hot roof when for a stroke of the pen you can specify cool? Why wait for Title 24 in April 2009?
You can get "Cool" but without the stone coating - just a plain Kynar painted surface.This will obviously be slippery when wet & look too shiny/fake -I need to avoid that!
So far the only candidate I have found is a future product(intro date unknown) from Gerard/3m that will meet my spec.
Anyone know of a specific ,named alternative?
Tony Davenport
2007-07-13 13:33:51.000000
I have checked most of these sites very carefully and all fail to meet at least one of the criteria
1.Stone coated
2.Shake appearance
3. Cool = 25%+ reflectivity
Decra meets 1 & 2 but fails on #3.
Custom Bilt Titan fails on #1.
Most achieve #3 by using light/shiny colors like white or silver.That is unacceptable with many CC&R's.
As far as I know Gerard+3M are the only manufacturer with a future product that will meet all 3 criteria.Please correct me if I am wrong.
Thanks, Tony
Tony Davenport
2007-07-16 13:41:37.000000
I think I have an answer to my own question but wanted to check with you the EXPERTS! I added a fourth requirement. Self-venting seems a good idea - why incur the cost+time of installing battens and counter-battens on an existing deck if you can get effective ventilation without them?
The answer is:Dura-Loc.
Buried in their technical specs are all 3 of my original requirements plus a claim of being self ventilating. Until I physically see the panel,I can't be sure.The TSR of their stone-coated "Driftwood" is 36%!
Any better ideas?Does Metro have anything?
Tony Davenport
2007-07-16 19:48:32.000000
I should have logged in & cited a source for my interest in the venting issue ,other than the 2009 Title 24 requirement. It is a publication mentioned elsewhere on this site:
"The effects of infrared blocking pigments and deck venting on stone- coated metal residential roofs." William Miller January 2006 .Oak Ridge National Laboratory.
See the conclusion on page 33 - I paraphrase;
stone-coated light gray with battens+counterbatten venting gave a 70% reduction in heat flow penetrating the ceiling.The key is that the manufacturer uses IrBCP's = Infra red blocking color pigments on the granules.
On p.17 in the Executive Summary : underside of shakes is bare metal(actually it was galvalume coated?) & acts as a built-in radiant barrier -IF it is vented.
Tony Davenport
2007-08-10 17:58:40.000000
Todd, Thanks for your kind words.
I found the 3/4" air gap reference for Title 24 in two places :
1. On page 63 of "Metal Roofing" August/September 2007.It is buried at the bottom of the table titled "2008 Title 24 Prescriptive Standards for Cool Roofing.For permit approval prior to 2009, the 3/4" gap is still a big issue because of the validation given by the Oak Ridge data cited in my previous post.Why the marketing people aren't all over this I can't understand.
2. The other source is Jon Wilson at RAM 1 877 638 2576. He'll probably refer you to his brother Jim at Metro who will refer you to Peter Croft (who is never in the office!).Yes,it took a lot of chasing to winkle this information out of the experts.
The significance of battenless compliance with Title 24 2009 at less cost with dark pigmented ,stone-coated shakes seems a well kept secret! Hopefully my point isn't lost on the astute members of this Forum and alternatives will quickly emerge.Just please let me know what they are.
Tony Davenport
2007-08-11 00:13:09.000000
The link I gave for Kool Blue doesn't work ,so here are the specifics:
Product Name : "Palisade SA.HT" (means self-adhering ,high temperature)
website http://www.sdp-products.com
Mfr. SDP Advanced Polymer Products,Toronto 1-866 747 4035
Tony Davenport
2007-08-12 13:09:47.000000
Has anyone looked into Steelrock's products?
website: http://www.steelrockroofs.com
Can anyone tell if they meet the requirements of a "cool roof" or energy star?
Are there any advantages to the different mfg's ?