Grumpy said:It claims less wrinkles but the few times I have used it, it had more wrinkles than a typical #30 organic... so that leaves me with the question, less wrinkles than what? #15? We don't use #15 so were still with the #30.
I'm not sure on the perm ratings but I have heard the GAF fiberglass felt has a higher perm rating that typical #30. Meaning it takes more water to make it leak.
I have been giving thought to the Roof Guard II synthetics. It looks like a promising product and perhaps what you lose on material cost (because it costs more) you make up for on production (because it's a larger roll).