It is kind of obvious if you think about it: Water runs down. So, when protecting against water intrusion, that is the direction it is most likely to be coming in from. Obviously there are times when wind-blown rain might be an issue too. This photo is not unusual. It is the south side of a beach side cabin. The big blue flashing is for a small attached shed that has a metal roof. This flashing is fairly high, not too far below the eave, but it would be much better if there was a counter flashing above it. That would ideally be a flashing that comes down over it from above and was high enough that no rain could ever get over the top of it during a storm. Such a flashing would route rain right down the wall, over the flashing in the photo and the water would then be discharged by the gutters and downspouts. As it is, while this area will probably not get too much exposure in this location, some wind blown rain during a beach storm might make its way in behind the flashing. I am not concerned about the shed, but that flashing is attached to the house and composition material, like the T1-11 siding, is not so fond of retaining moisture. Plus, the grooves in the T1, that run behind the flashing, are prone to routing water right behind the flashing and, even if caulked, that is a maintenance flashing that gives way after not too many years. When trying to figure out where a leak might come from, try to imagine how water flows.

 Thanks for dropping by.

Steven L. Smith

www.kingofthehouse.com