Your roof and vents look just like the setup I had on my old SB greenhouse. Personally, I doubt that putting any shade on those vents would matter much in any season. When it's hot, they will be open, and in winter so little light comes through them anyway because of the angle of the sun and the closeness of the house. Bob _______________________________________________ pbs mailing list pbs@lists.pacificbulbsociety.net http://lists.pacificbulbsociety.net/cgi-bin/… Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net>