Thanks everyone!

You gave me some ideas to think about.

I should have mentioned my home is pitched roof and not a flat roof.

The installer I am talking to said they use a felt that has titanium in
it so it holds up well to any exposure to sun light which tends to
destroy the usual felt. I understand the felt is what prevents leaks.

I asked some local homeowners about their tile roofs and they seemed
happy. One even installed concrete siding and it really looked good.

I plan on calling in a number of installers for estimates and that way
I can learn more as they each explain their products and methods.

I talked to one person in California that was denied a home loan on a
house because the house next door had cedar shake windows and the bank
was concerned about the fire danger from the other house!

I might also check out some of the metal products but they don't seem
as popular.

Thanks again, and please do add any comments or ideas you think might
help.

- Bob