I've been looking at the NHBC guidance for all chimneys and hoped someone could help. The page shows three drawings of DPCs in chimneys, two of which are on pitched sections of roof. I am understanding this as two alternatives, not that there should be a damp tray at the top junction and at the bottom junction. The one with the tray at the bottom 'junction' is on the eave of the roof. Can you use the other approach at the eave instead? Does anyone have a preference for which of the two approache