Which flashing is correct?

Up on a flat roof today with roll roofing. Drip edge flashings all around.

But half the edges have the drip edge flashings under the roll roofing and the other half has the drip edge flashing over the roll roofing. Which is correct?

It did not appear that the half that was over the roll roofing was installed on top of older flashing that was under the roll roofing.

I’m also suprised there isn’t more tar sealing the roll roofing edge/flashing seam.

What gives? :eek:

PS: Sorry… the picture isn’t the greatest because of the shadow. Over is on the right and under is on the left.


Jeff, Drip edge should run under the roofing material at the bottom and ends of the roof.



It really depends on if it ponds water or not. If it doesn’t you can run the drip first and use cold process modified and glue the bottom of it to the top of the drip edge. I like to give it a 1 inch overhang if so. This is mainly for houses. But if it ponds water like on commercial buildings you have to run torch grade modified. They run the field first, install the drip edge and prime it, and then strip it in with a 12 inch strip or torch modified.
BTW, that pic looks like it’s defiantly leaking.