Drip edge flashing

[Danny Pritchard]

Inspected a light commercial building today with parapet walls on three sides.The roof drained to the rear of the building.The attached picture shows the drip edge flashing above an area where staining has occurred on the ceiling tiles.This is a rolled roof ,shouldn't the flashing have a flat top versus the upturned edge?

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[hausdok]

Hi Danny,

That's not actually a drip-edge flashing. It's a gravel stop. Usually see those with a built-up roof and several nice thick layers of felt and tar bonded to it with a layer of gravel ballast on top.

ONE TEAM - ONE FIGHT!!!

Mike

[mgbinspect]

Mike and Danny,

Judging by the size and consistency of the aggregate against the size of that screw driver blade and also considering the fact that Danny said it's rolled roofing, I'm guessing that what you're looking at is what's called "Selvedge" (Premium quality organic mat impregnated with asphalt saturant and high grade weathering asphalt.) It has an aggregate finish just like asphalt shingles, (typically white). It's put down with cold adhessive method. It actually has more the feel of modified rubber. It's a pretty durable roofing material. Good stuff!

http://tamko.com/Portals/0/documents/19 ... pp_ins.pdf

That gravel stop looks typical.

[RobC]

Selvage (rolled roofing) is seldom used here in commercial work. It's usually considered as a temporary, low quality, temporary fix.

What you might have is a 'Modified Bitumen' roof membrane that would appear to have been torched on. Although this material looks like selvage, its properties are light years more advanced, and durable than rolled roofing.

If so, I would question the need for a 'gravel stop' as there would be no gravel to stop.

How is the roof draining?

Scuppers, Troughs

or

Roof Drains

How much staining are we talking about?

[mgbinspect]

Yup, you beat me to it, Rob.

I was about to correct my previous post. For some reason, roofers around here have nick named it selvedge, but it's not an asphalt product. As soon as I began researching it I realized the "name" is wrong. It is as you said 'modified bitument' which seems to be a pretty good and durable material.

This is the material I was referring to:

http://www.nombach.com/FlatRoofs.asp

Sorry for the mix up.

Mike

[Danny Pritchard]

How is the roof draining?

Scuppers, Troughs

or

Roof Drains

What you see is where the roof drains.The staining is about a 1' square area.The Manager of this store said it has grown since he has been there which is about 10 months.Apparently it is not a very active leak.

This building is 4 years old.My thought was that the drip edge will hold water and become an issue over time.

Thanks Mike for confirming the gravel stop.That is what I thought when I saw it.Typically on roofs like this the flashing is flat the roofing extends past the edge of the flashing so there is no chance of water slipping beneath the roof material.

My question is did the roofer use the wrong flashing or is this flashing acceptable even though it allows water to pond at the edge?

[hausdok]

Hi,

I say he used the wrong material. Roofs done that way around here typically extend out beyond the edge of the roof and droop into the gutter a little bit or end right at the end of the wall on top of a piece of coping. Some of them even install a piece of one-by material along the top of the wall with a piece of drip edge. They adhere the cover to the top of the drip with mastic and extend it just beyond that so it and the gutter are clear of the wall.

ONE TEAM - ONE FIGHT!!!

Mike

[mgbinspect]

Interesting! Here I most often see this material installed just as you see it, glued down onto that gravel stop or whatever you call it, which has always bugged me too. The material is tough as nails, though and about 3/16" thick. The edging looks fragile, but whatever they use to seal it down rarely comes apart.

[mgbinspect]

Here are some industry standard details for installation of this material:

http://www.certainteed.com/NR/rdonlyres ... ashing.pdf

And, here is a great resource showing all details for installing modified bitumen:

http://www.certainteed.com/CertainTeed/ ... /LowSlope/

Hope it helps.

[Steve Boozer]

Test picture:

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[Steve Boozer]

Cool, I got it on the first try.

[hausdok]

You've got some weird beasties where you are.

OT - OF!!!

M.

[StevenT]

If that is where the roof drains, shouldn't the drip cap or end cap or whatever you install there be installed under the roofing so the water drains over it?

Since the edge appears to be raised, I agree that it is a gravel stop and would be the perfect edge for somewhere else. I usually see gravel stops on hot tar w/ stone roofs. I've also seen similar profile material on the rake edges of roofs or flat roofs w/o parapits. In most cases all that is usually seen is the raised lip, not the entire profile. (Occaisionally, I've had roofers tell me they install a similar profile over roof tiles edges @ rake ends to help protect against wind damage)

Do you think that the direction that is is installed and the fact that there is a raised edge, would collect water all along the edge. And if there is a water problem, isn't that probibly a very good place to suspect.

- Steven Turetsky, S.I.,N.Y.

[Phillip]

Back when I installed metal for the built up roofing. They installed the roof to the edge and had a bleeder felt installed that run from under the bottom of the roof. I took roofing cement and seat it to the top of the roof. Then added more roofing cement Than nail the metal edge Be it gravel stop or other in place. We lapped the metal about 3" with a layer of roofing cement between the pieces of metal. Then the roofer came and stripped the metal off with layers of roofing. Then they installed the top of the roof with gravel or a cap sheet. When we use the gravel stop we cut and installed supper in any that was over a half inch tall to let the water drain. Your set up looks like they should of used a flat drip edge. IMHO