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RicodJour RicodJour is offline
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Default why does drip edge go over membrane?

On Sep 29, 10:15*am, HerHusband wrote:
Hi George,

On a pitched roof, my understanding is that the rubber underlayment
should go down first, then the drip edge. *I'd have thought that the
drip should go first: then, any water captured by the membrane would run
off over the drip. *I can guess that putting the membrane first lets the
it seal the drip nails. *But, to what end, if there's no place for the
water to go?


When I shingled our roofs, I installed the drip edge along the bottom of
the slope first, then installed my roofing felt over the top. This way if
water finds it's way under the shingles, in theory it should flow down on
top of the felt, then over the drip edge. *If the drip edge were on top of
the felt, the water would go under the drip edge to the wood decking. *I
don't see why membrane would be any different.

On the sides of the roof slope, I installed the drip edge after installing
the felt. This keeps any rain that may be blown under the edge of the
shingles on top of the felt, and not blown under the felt to the wood.

On top of the drip edge at the bottom.

Under the drip edge on the sides.


Interesting timing. I just returned from the library and the current
issue of Fine Homebuilding answered this very question. There take
was that the membrane should be under the drip edge, and wrapped over
the top of the fascia (hidden by the drip edge). I never did it that
way, but it makes a lot of sense, particularly in ice dam territory.

R