Last shingle at gable lifting upwards ?
I am roofing a shed in my back yardÂ
As shown in the diagram below, at the gable end of a roof, the metal flashing that is normally added, tends to lift the last shingle upwards giving it a negative slope towards the roof. This seems to cause some water to follow the contour of this last shingle and some water ends up between the shngles and the tar paper. Since this is the edge of the tar paper, some water inevitably finds itÂs way on the roof deck.
Is this really a problem, and if so, How do I get around it?