Drip edge on a low slope porch.

markcal02 · 10-03-2011, 10:44 AM

What is the best way to attach drip edge to a low slope porch?

AGWhitehouse · 10-03-2011, 01:40 PM

Are you asking how to flash it? Attachment is via nails...

markcal02 · 10-03-2011, 02:10 PM

Sorry about being so vague in the way i asked the question.

Does the drip edge go under or on top of the underlayment/felt?

AGWhitehouse · 10-03-2011, 02:15 PM

It goes under the felt

markcal02 · 10-03-2011, 04:54 PM

I posted the same question in the "This old house" forum and got this reply- it should go over the felt.. the metal drip edge will sweat and cause the edge to rot.. seen it several times.. same goes for ice and water sheild

Which answer is the correct one?

AGWhitehouse · 10-03-2011, 05:05 PM

It will sweat? That just makes me confused...

As far as what is correct, think about it. Water flows downhill, so you place items in the assembly to shed water. The drip edge is the last thing the water touches before it leaves the roof. Assuming the shingles themzelves aren't there yet; the water runs down the felt, onto the drip edge, and off the roof. If you place the drip edge on top then the water will run down and under the drip edge down the fascia, across soffits, into walls, insulation etc. For those that say caulk it on top, I emplor that the definition of a bad design is one that relies on caulk for water tightness.

Here's an image: http://www.inspectapedia.com/BestPra.../Figure2-6.jpg

Edit: Just realized the attached image has the drip edge on top on the rakes. This is correct and may be adding to the overall confusion. Final answer: On top at the Rakes (Gables), On the bottom at the Eaves (Soffits).

Slyfox · 10-04-2011, 07:21 AM

The best correct answer is to go manufacturers website (manufacturer of the shingles your installing) and click on installation spec's and read what they want.

I always run felt over the drip on the eaves and under on the drip gables.

shazapple · 10-04-2011, 08:49 AM

AGWhitehouse is correct. Drip edge goes under felt at the eave, over at the rakes. This is how it is detailed in the NRCA (National Roofing Contractors Association) Steep Roof Manual.