Small Cabin

Small Cabin Forum
 - Forums - Register/Sign Up - Reply - Search - Statistics -

Small Cabin Forum / Cabin Construction / Drip Edge on Roll Roofing
Author Message
paulz
Member
# Posted: 5 Oct 2018 22:58
Reply 


This link shows the drip edge on the gable end nailed over the roll roofing, is that correct?


http://thefavorite.info/rolled-roofing-installation/rolled-roofing-installation-roll- roofing-installation-rolled-roofing-installation-earth-rise/

Absolutely
Member
# Posted: 6 Oct 2018 11:49 - Edited by: Absolutely
Reply 


Yes it it's underlayment that you're talking about. At the eave, I'd guess that if you install the flashing under the roll roofing you'd risk getting moisture between the flashing and the roll roofing.

"Metal D flashing, or drip-edge, is sometimes installed only along the eaves edge, but it is actually required by the 2012 International Residential Code (IRC) “at eaves and gables of shingle roofs.” At “gables,” of course, means along rake edges. The purpose here is to help prevent wind-blown rain and capillary action from directing rainwater and snow melt underneath the underlayment and shingles."

from here: https://www.jlconline.com/how-to/roofing/common-roofing-errors_o

NorthRick
Member
# Posted: 6 Oct 2018 11:56
Reply 


On a shingled roof, I've always installed it under the shingles on the gable ends. But with the rolled roofing, my guess is they want it on top to prevent wind from getting under and lifting the rolled roofing.

If it were me, I'd install it like they show with a generous bead of caulk laid down on that edge before setting and nailing down the drip edge.

ICC
Member
# Posted: 6 Oct 2018 12:07
Reply 


In the link the first image shown (with the drip edges) is for underlayment, not roll roofing. Gorilla Giard is an underlayment, roofing felt, also known as tar paper. Yes, in that case, the rake (gable edge0 has the drip edge applied over the underlayment. The eve has the drip edge under the underlayment.

With roll roofing, you can find installations that use underlayment and those that do not. I would do whatever the manufacturer of the roll roofing recommends.

I have seen roll roofing with the rake having the drip edge over the roofing and nailed and tarred and I have seen the drip under with the edge of the roll roofing extending over just as would be done with shingles.

I've actually never used roll roofing. Even my chicken coops usually had metal.

rockies
Member
# Posted: 6 Oct 2018 18:00
Reply 


This article may help.

https://homeguides.sfgate.com/install-roll-roofing-low-slope-roofs-21346.html

One detail I saw on a site discussing common mistakes made when reroofing is that most people install the drip edge (at the eave) with the edge tight up against the fascia. This tightness can cause water to leak backwards (and actually upwards) to soak the fascia. They recommended adding a 1/2" x 1" strip of pressure treated lumber to the top lip of the fascia before attaching the drip edge. This moves the bottom of the drip edge further way from the fascia so water will drip into the gutter.

paulz
Member
# Posted: 7 Oct 2018 10:21
Reply 


Ah, the underlayment. Sorry, missed that. Thanks for the other advices.

toyota_mdt_tech
Member
# Posted: 7 Oct 2018 10:39
Reply 


My metal roof flashing goes over the top of the metal roof, but it is sealed with butyl tape too.

Borrego
Member
# Posted: 7 Oct 2018 15:45
Reply 


May be different with whatever Gorilla Guard is, but with all roofing I've seen done right, the drip edge goes on the wood deck, then paper, then roofing material. Used to find a lot of roofs with the drip edge installed over the paper...usually rotten plywood underneath. Makes sense if ya think like a raindrop....

ICC
Member
# Posted: 7 Oct 2018 18:20 - Edited by: ICC
Reply 


Quoting: Borrego
the drip edge goes on the wood deck, then paper, then roofing material.


Depends what edge of the roof you are talking about. On the rake of a gable roof the drip edge metal goes over the paper, as shown in the first drawing in the OP link, but on the eave the drip edge metal goes on first and then the paper over that. Read the last line in the attached image.
drip
drip


Borrego
Member
# Posted: 7 Oct 2018 19:31
Reply 


Quoting: ICC
Read the last line in the attached image.


Got it...nonetheless, most roofers i work with always install drip edge under paper. If water gets through shingles or roll roof, it can migrate along the paper and up under the metal edge material. I can see it both ways.....but I'm not one who always agrees with a theory just because it's in the code book.......

ICC
Member
# Posted: 7 Oct 2018 20:31
Reply 


Well, what I was taught is the idea behind covering the rake ends of the felt paper, or other weather resistant barrier, with drip edge ensures that windblown rain that gets under the shingles will run over the underlayment, not on the sheathing.

ICC
Member
# Posted: 7 Oct 2018 20:40 - Edited by: ICC
Reply 


There is an exception I can think of. I forget the brand of ice-barrier it was, but the mfg recommended lapping the bottom edge over the fascia board at the eaves and then installing the metal drip edge over that. Any water than seeped under the metal was prevented from contacting the roof deck or fascia by the self-stick ice barrier. They had performance reports verifying that was okay and the inspector would pass that.

roniemarkes
Member
# Posted: 14 Feb 2024 01:53 - Edited by: roniemarkes
Reply 


For installing drip edge on roll roofing, it's key to start with the drip edge along the eaves first before laying down the roofing material. This way, water gets directed off the roof and away from the structure. After the roll roofing is in place, you can add drip edge to the rakes for a clean finish. Make sure everything's nailed down securely and sealed to prevent leaks. It's a straightforward process, but getting it right can really protect your building from water damage.

Your reply
Bold Style  Italic Style  Underlined Style  Thumbnail Image Link  Large Image Link  URL Link           :) ;) :-( :confused: More smilies...

» Username  » Password 
Only registered users can post here. Please enter your login/password details before posting a message, or register here first.