A cautionary tale about a roof that was sealed with spray foam but not ventilated. The more I read stories like this the more important roof ventilation appears to be. All my plans have it but unvented roofs have been popular where spray foam is used. It appears that for this to work the foam coverage has to be perfect - hard to do in the real world.
http://www.jlconline.com/cgi-local/viewnew.pdf/0/36d788c301e849ce97885b518ca065ce/www.jlconline.com/cgi-bin/jlconline.storefront/4c17bfc20ae738db27170a32100a0668