Sensisble to request ice & water shield on whole roof?
 

Does it make sense to request ice & water shield throughout whole roof for underlayment instead of 2 layers of felt paper, for asphalt shingle roof.

Part of the roof is low pitch 2:12 (with rest at 4:12), and roofer bids either don't specify using the ice & water shield or only at parts of the roof. I assume whole roof means more $, don't know how much more. Just wondering if it was ever abnormal to request it for the whole roof.

My local is northern California, if that matters.

A 2-12 pitch is the absolute minimum for most shingles.
You would be far better off to concider another form of roofing on that low a slope.
EPDM, metal, there's also several other types that would work out far better.

I think that I & W on the whole roof would be a waste of your money. In your location, I would question the need for I$W anywhere on the roof as you do not get any snow to worry about ice damming.

Joe is correct about the low slope roof.

Andy.

thanks I'll bear your comments in mind.