I’m preparing to reroof my home. I’m going to be using Athentic Roof 2000 with copper eave, rake, and valley flashing. I’m confused about what to use under the valley flashing. Some of the posts here and in FHB 152, ice and water shield is being used. The Grace web site states not to use this product under copper flashing. So what’s the deal? In the same vein. Should the ice and water shield go under or over the eave and rake flashings? I am thinking it should go over to make a better seal.

Thanks

TSMartin