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David Axt, AIA, CCS, CSI Senior Member Username: david_axt
Post Number: 992 Registered: 03-2002
| Posted on Friday, March 07, 2008 - 05:28 pm: | |
Is there a better way of classifying the quality of asphalt shingles rather than the manufacturer's perceived lifespan? Is there an ASTM classification or test? |
Anne Whitacre, FCSI CCS Senior Member Username: awhitacre
Post Number: 733 Registered: 07-2002
| Posted on Friday, March 07, 2008 - 07:12 pm: | |
generally the difference is the weight per pounds per hundred square feet. |
David J. Wyatt, CSI, CCS, CCCA (Unregistered Guest)
Unregistered guest
| Posted on Thursday, March 13, 2008 - 08:59 am: | |
Anne, Ergo: should we associate durability with how heavy the shingle is. Makes sense. It's a struggle to get architects off of "fiberglass shingles." Yes, fiberglass is a component of fiberglass-reinforced asphalt shingles, but not the primary one. I prefer to title such a section "Asphalt shingle roofing" and then get into the details in the section. By this point, usually I have lost the architect, who regards spec writer as an eccentric. |
James M. Sandoz, AIA, CSI, CDT, LEED AP Senior Member Username: jsandoz
Post Number: 31 Registered: 06-2005
| Posted on Friday, March 14, 2008 - 09:50 am: | |
Eccentric? That's a good thing right? I had a supervisior once who said I was "quirky." Is there some standard that addresses how well the mineral granules adhere to the substrate? In my mind that seems like a good predictor of the life span of the product. |
David Axt, AIA, CCS, CSI Senior Member Username: david_axt
Post Number: 993 Registered: 03-2002
| Posted on Friday, March 14, 2008 - 12:19 pm: | |
So nobody has answered my question.... How do I specify asphalt shingles without naming specific models? |
George A. Everding, AIA, CSI, CCS, CCCA Senior Member Username: geverding
Post Number: 409 Registered: 11-2004
| Posted on Friday, March 14, 2008 - 01:00 pm: | |
ASTM D 3462-07: "Specification for Asphalt Shingles Made from Glass Felt and Surfaced with Mineral Granules" is one reference standard for shingles. Also try ARMA at asphaltroofing.com |
Ralph Liebing, RA, CSI Senior Member Username: rliebing
Post Number: 796 Registered: 02-2003
| Posted on Friday, March 14, 2008 - 01:04 pm: | |
David, I found a "historical" ASTM standard [whatever that means] on their web site. Recall its was D228-05, 05a and 05b. Then an "Active" standard, D228-06. None of these are specifc to shingles but to all forms of asphalt roofing, but may have some relevance to you. |
John Bunzick, CCS, CCCA, LEED AP Senior Member Username: bunzick
Post Number: 861 Registered: 03-2002
| Posted on Friday, March 14, 2008 - 02:31 pm: | |
If the construction of the shingles of differing warrant duration is essentially the same (as it appears to be), with the possible exception of weight, and all meet the applicable ASTM standard, then I would posit that the shingles 'quality' is established by the standard and all you need to do is specify the warranty duration. Why make it more complicated than it is? |
John Bunzick, CCS, CCCA, LEED AP Senior Member Username: bunzick
Post Number: 867 Registered: 03-2002
| Posted on Wednesday, March 19, 2008 - 02:24 pm: | |
To Mr. Sandoz' comment; I just happened across this test while reviewing Lafarge's abuse resistant drywall, where they used it on gypsum board. ASTM D4977 "Standard Test Method for Granule Adhesion to Mineral Surfaced Roofing by Abrasion." Maybe the shingle manufacturers have this testing available. |
James M. Sandoz, AIA, CSI, CDT, LEED AP Senior Member Username: jsandoz
Post Number: 32 Registered: 06-2005
| Posted on Thursday, March 20, 2008 - 09:14 am: | |
John, I should not be surprised (and I'm not) that there is an ASTM standard for granule adhesion. It is interesting that LaFarge used a modified version of that test to quantify abrasion resistance for its abuse resistant drywall though. My cursory investigation of ASTM standards turned up many abrasion test procedures for everything from organic coatings to apparrel for motorcycle riders but nothing specifically for gypsum board. I had a conversation with a Georgia-Pacific representative a few years ago about their abuse-resistant gypsum drywall product. I was with a firm then which focused on K-12 projects. We were of, of course, primarily interested in impact resistance but abrasion resistance was discussed as well. One might think abrasion would not be a problem for sloped, asphalt shingle roofs but it can be. My first "real" job in high school, apart from flipping burgers at the Orange Julius, was as a "gopher" for a residential roofing contractor in Houston. I saw asphalt shingle roofs that had been damaged from tree branches rubbing against them for prolonged periods of time. Worse than that though were the gouges that were made in the granule layer when something heavy was dragged across the shingles on a HOT summer day. Asphalt softens when it gets hot and I'm not sure how the mineral granules can be made to stick better to their substrate but that quality must be a factor in the longevity of the product. |
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