http://www.karnakcorp.com/
This is what I am most familiar with for roofing
http://www.karnakcorp.com/P_RP_RMTapes.aspx Scroll down to 19AF.
It stays pliable for years, but does dry, harden and crack.
And made in New Jersey, so it's pretty much everywhere and why I really don't see much else.
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Just tried to PM this to you JCWIT, but you are not accepting PM's
you got me thinking instead of sleeping, but this is a waterproof "fabric" that is tough as anything and [censored] new impossible even applied cold to get off of plate steel and asphalt/tarmac/concrete...
For a 4' x 8' section, it takes about 15 minutes with a 175,000 BTU torch and front end loader on pavement (being careful not to scorch blacktop or pop concrete, and about 25 mins for the same 4ft x 8ft piece on those metal plates you may see on a road, which is more or less burned and scraped off. So, it adheres pretty much forever to metal. (sound deadening idea popping into my head)
Petrotac
http://www.nilex.com/products/paving/petrotac
If you can get bare steel, this could be a long term solution, but you would need light heat and a small wooden roller to make sure the adhesive touches everything. Just an idea