"Edwin Pawlowski" wrote on 16 May 2007 in group
alt.home.repair:

I'd avoid drywall as it would probably get damaged by moisture. If
money was not an consideration, cypress would be great. I'd
seriously look at some sort of vinyl siding material. There is a
vertical style that looks like board and batten that may look good up
there.

I'll second the nomination to NOT use drywall. I have a job next week to
replace some 30-year-old soffit that was done with drywall. Squirrels
gnawed through it, built a nest, and caused the drywall to fall off.

On the other hand, it DID last 30 years....