What shingles for long life on 3/12 pitch roof in Olympia, WA.

[vettespeed]

Hello,
I will be starting construction of a new detached garage/shop that has a 3/12 pitch roof. This is a nice residential waterfront community and I want something that looks nice and appropriate for the area. I hate the look of "flat roof" membrane type roofing and am not a big fan of metal roofs. My contractor and the roofer he uses are suggesting Certainteed Presidential shingles due to the “Low Slope”. My question is: Do these shingles perform better and have a longer life span than a typical “Lifetime” architectural shingle? I do not care about the aesthetic appearance of the “Presidential” and any nice “Lifetime” architectural shingle would be fine. That being said, are these shingles overkill for what my priorities are? I’m assuming they will come in quite a bit pricier then the architectural shingles? I’m quickly looking at retail prices of GAF Laminated Architectural Roof Shingles at $91.92/square and Owens Corning Laminated Architectural Roof Shingles at $77.85. We will be using Ice and Water Shield and the appropriate methods for the low slope roof. Is the double felt method a better way to go than the Ice and Water Shield? Issues with Ice and Water Shield acting as a vapor barrier? I’m looking for advice.
Thanks.

 

[ree]

vettespeed, Hi, this is a UK based DIY site. Why not google some of the Professional USA based roofing forums?

FWIW: to get attention and advice why dont you cut your question down to one simple sentence/line, you can always then begin to add on?

 

[vettespeed]

Oh, didn't realize it was UK.