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Circle-D Posted: Jun 04, 2008 10:04 PM	over heated roof Hi Everyone, I had a contractor ask me today about unvented roof assemblies. He said he had heard about unvented roofs getting so hot that the shingles would curl and the ice and watershield would actually liquify and run down over the fascia board. Has anyone ever heard of this? He has sent Certainteed an e-mail about the shingle issue and was going to send one tonight to Grace about the ice and watershield issue. I told him I thought Certainteed warranteed there shingles for unvented roof assemblies. I also said I would post this question here for all to respond to. Share your thoughts, thanks in advance.
Doug Commette Posted: Jun 05, 2008 01:22 PM	There is another forum thread that discusses this issue in more detail. Here is the link: https://sprayfoammagazine.com/mnps/fullthread.cfm?threadid=5455&mnboardid=5&mnforumid=2&startat=1 I also added the direct link at the side. Below is some nice info from Mason that I share in too: By the way, independent researchers (non sprayfoam guys) who have studied the issue agree that unvented attics do little to affect the life of a shingle. Other factors affecting the temperature of the shingle more include: Color of the shingle Direction the roof is facing How hot the climate Funny, but the shingle manufacturers do not exclude shingle warranties in hot climates or that facing the East or West or that are dark colored. Carl Cash (former chair of ASTM Roofing Committee and recipient of their prestiguous Cullen Award.)opined in a research paper he presented at the RICOWI seminar in 2001 that he would love to testify in court against a shingle manufacture who was trying to enforce that warranty exclusion. To be consistent Cash observed that shingle warraties would only be valid in climates similar to Minnesota facing South that are white in color.

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Circle-D

Posted: Jun 04, 2008 10:04 PM

over heated roof

Hi Everyone,
I had a contractor ask me today about unvented roof assemblies. He said he had heard about unvented roofs getting so hot that the shingles would curl and the ice and watershield would actually liquify and run down over the fascia board. Has anyone ever heard of this? He has sent Certainteed an e-mail about the shingle issue and was going to send one tonight to Grace about the ice and watershield issue. I told him I thought Certainteed warranteed there shingles for unvented roof assemblies. I also said I would post this question here for all to respond to. Share your thoughts, thanks in advance.

Doug Commette

Posted: Jun 05, 2008 01:22 PM

There is another forum thread that discusses this issue in more detail. Here is the link:

https://sprayfoammagazine.com/mnps/fullthread.cfm?threadid=5455&mnboardid=5&mnforumid=2&startat=1

I also added the direct link at the side.

Below is some nice info from Mason that I share in too:

By the way, independent researchers (non sprayfoam guys) who have studied the issue agree that unvented attics do little to affect the life of a shingle. Other factors affecting the temperature of the shingle more include:
Color of the shingle
Direction the roof is facing
How hot the climate

Funny, but the shingle manufacturers do not exclude shingle warranties in hot climates or that facing the East or West or that are dark colored.

Carl Cash (former chair of ASTM Roofing Committee and recipient of their prestiguous Cullen Award.)opined in a research paper he presented at the RICOWI seminar in 2001 that he would love to testify in court against a shingle manufacture who was trying to enforce that warranty exclusion.
To be consistent Cash observed that shingle warraties would only be valid in climates similar to Minnesota facing South that are white in color.

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