Your roof is your home’s main line of defense against water intrusion. It gets baked by the sun, drenched in the rain, and covered by snow and ice. It is the workhorse of your house and does its job without complaint, but there is one little detail that is missed by way too many roofers that causes big time damage to your house.
It’s not valley flashing or underlayments, though those are just as important. It’s something so simple and it is blatantly obvious if you know what to look for.
In fact, this issue is so common that a lot of the localities and even contractor training classes teach roofers to do this incorrectly.
The Drip Edge
For any asphalt shingle roof, a drip edge is required by most local building codes. What is a drip edge you ask? It is a small piece of “L” shaped metal with a little kick out on the edge that goes around the perimeter of your roof. Its purpose is to give water an edge to drip safely off your roof onto the ground or into the gutter.
I haven’t seen a roofer forget the drip edge, but I have seen WAY too many who have no idea how to install it properly. Without proper installation, it is completely pointless.
Look at the picture below and you can see the wrong installation on the left and the correct way on the right.
How To: Properly Install Drip Edge
This small little detail is incredibly important! I can’t stress this enough. The drip edge should be installed over a piece of 1×2 furring strip so that it stands off from the fascia or rafter tails.
If the drip edge is laid right up against the fascia or rafters, then because of surface tension, the water runs right up against the fascia and underneath the soffit.
You want water to stay off your house if you hope to avoid rot. This lazy installation causes all kinds of damage to much more than just the fascia. It creates soggy siding, encourages termite activity, and hugely increases any potential for rot.
A lot of roofers may disagree with me on this, saying that the kick out on the drip edge does its job without needing the furring strip, but experience is the greatest teacher. I’ve watched the water run down fascia boards and rafter tails on rainy days with the drip edge doing little if anything. So, in my opinion, there is only one way to install a drip edge properly, and it’s with the furring strip.
I have to think the problem is mainly ignorant roofers. I noticed the problem for years, but it wasn’t until my friend Steve Quillian of Wood Window Makeover kept ranting about it that I started to look for it.
And it is amazing how rampant this problem is. I’d say that close to 40% of the homes I see have this problem. It can be remedied fairly easily by a roofer for very minimal cost. And it honestly wouldn’t have cost anymore to do it the right way the first time. You just have find a roofer who knows what he is doing.
Check out your house and be a good neighbor by looking next door too. Hopefully, your home is protected. Knowing is half the battle. (Yes, I stole that line from GI Joe but, hey, it’s true!)
If your drip edge is improperly installed, I would call a local roofer and get it looked at immediately. The sooner you fix this, the sooner your house will be protected.
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I love old houses, working with my hands, and teaching others the excitment of doing it yourself! Everything is teachable if you only give it the chance.
71 thoughts on “How Your Roofer is Destroying Your House”
So if my drip edge is installed like in your incorrect photo, would you recommend sticking something behind the drip edge to fur it away from the fascia? I’m not going to have it all replaced, but would like to do my best to prevent issues. I’m in Southern California and we are not a terribly wet place. Thanks.
Tuck flashing that has an outward bend underneath the drip edge.
what about ice dams going behind the drip edge if installed like this
We are thinking of replacing our asphalt roof with a metal one. 1910 Midwestern Farmhouse. Any reasons not to or things we should keep an eye out for if we do this. The problem is where we live no permits have to be pulled for anything. Thanks
I recently had my roof replaced and… long story short, the drip edge was originally installed correctly, then the gutters were installed and they messed the drip edge up. After I noticed this, the roofer came back and reinstalled the drip edge pretty much all the way around the house. When he replaced the drip edge, he nailed through the top of the shingles. I would assume that this is not the way to do it and will cause serious problems in the very near future but just wanted to get a second opinion (s). By the way, my regional building department did an “inspection” and it passed.
You should minimize exposed nail heads through the top of a shingle as much as possible. Vents, pipe boots, and starting point of a ridge or hip cap are only reasonable expectations. Did the roofer install leak barrier like WeatherWatch wherever there is drip edge? That might be fine for longer than you’d think, that tends to self-seal around a nail when punctured.
I have a 60 year old home and a carport with a low slope roof.
Mystically the plywood on the carport roof is all moldy for a 1 foot perimeter but solid on the rest of the roof.. I think a drip edge would help. Thanks for this blog !!
Water drips more behind my drip edge than infront..but in BOTH sides.Even though it is gapped away from fascia..the water that drips behind is wetting the Exposed Fur ing strip.another ques I have..wouldn’t it been better to cover fascia in 1 big alumin piece..an not just have it go on second an 1 inch short gap to an exposed fur..ing strip..
Scott, thanks for your post because it appears to address the exact issue I’m investigating. On my roof, there is a a 1×2 firing strip behind the drip edge. The drip edge is also about 2″. Maybe it is a tad longer than 2″. In any case, there is not gutter and I’m adding one. Is there any additional flashing or sealant required to protect the firing strip and facia? I saw a comment where you mentioned to avoid creating a moisture trap with sealant. However I was thinking to find a vinyl z-shaped flashing which could protect the bottom of the firring and the facia. Do you think this is necessary? I’m not the installer but want to ensure it is done correctly. Thank you Scott. Appreciate your attention to detail in this blog post!
Additional flashing never really hurts. Just think like water, see where it will go and make sure it won’t get trapped.
My parents recently had their roof redone. A drip edge was suppose to be put up but apparently the workers weren’t aware of that. Then they did the roof on their shed and installed a drip edge, that’s when my parents said they don’t want them to do the drip edge for the house. The drip edge on the shed… Well it looks horrible. I’m far from an expert. But I’m pretty certain that it should all at least look like one piece. They left a gap and “corrected” it by taking a piece and putting up above the other two pieces, above the gap… That is NOT how it should look.
Agreed it should look continuous. But they need that drip edge on the house or the roof sheathing will rot very quickly.
My builder face nailed the drip edge almost everywhere. Should I have him replace all the drip edge flashing? What would happened to the fascia boards? I am also installing gutters. He said the gutter installer will have to unscrew the nails. How much would all this affect my siding. All this was done during hardie plank siding installation.
He should replace the drip edge. Only an amateur would face nail the drip edge.
I don’t think this is necessary if using aluminum fascia and soffit. Although kicking out the DE is advisable for better gutter function. I see water dripping behind gutters all the time if the DE is tight up to the alum. fascia.. However, you will be creating a wonderful breeding ground for all sorts of insects and you lose the upper hold on the alum. fascia. Now you have to face nail and with face nailing comes crinkled alum. Fascia.
I’m sorry but this is horribly wrong. As a veteran roofer I have torn off thousands of roofs and dealt with rot and mold on many fascia and gutter areas.
The drip edge is NOT causing this issue!!
All one has to do is trace the stains. In most cases damage is caused by lack of ice and water guard at the gutter, or improper nailing and installation of the starter strip!
In some cases you are correct and drip edge is installed too close to the fascia and causes water to actually run behind the gutters but this is usually a compound problem where the gutters are hanging loose from the fascia.
The problem with your furing strip is that as water builds in the gutters it will actually wick up behind it.
I learned to roof from my father who learned from old generation europeans. We arent fly by night roofers we treat this as a trade and we see alot of bs installations. I have returned to happy customers of my father’s after 30 sometimes 40 years and torn off my father’s work to find nothing but quality in technique. You learn what works and what doesn’t from the old timers, and also from tearing off many old improperly installed roofs. I can honestly say that in all my years in the business I only had one call back, and it was caused by a defective product. Even my one call back customer remains a happy customer to this day and has referred friends to my work.
I am not bitter in any way and I seek no quarrel with anyone but I must advise against this technique. If you are concerned about water tracking, simply install the drip edge with a 1/4″ gap behind it that will take care of all your worries.
Always appreciate different ways to tackle the same issue. Thanks Vaughn!
scott, I have a roofer that has installed the drip edge but it is about 1/16th to 1/18 or touching. My painting of the facia has closed the gap in most areas. If this is not a good installation or action with the painting, then can I place a drip edge over this so that it overlaps into the gutter after the gutters are installed ?
Vaughn, where is your roofing company? Thanks
Thanks for the post. Do you recommend caulking the underside of the furring strip? I have a setup like the one you show with the furring strip in place, but also a gutter that sits below the drip edge – I’m worried there could be some splash from when the water lands in the gutter, but I’m not sure if caulking the area could potentially lead to other problems. Any thoughts appreciated.
Scott, I’d leave it uncaulked. Too much opportunity for trapping water.
I’ll have to disagree with this. In my area Carpenter bees will dig into a firing strip and make their way into the structure. We break our coil to sit tight right against the shingles, then bend our own drip edge tight against the fascia, no way for water to migrate up. I’d recommend using a composite material (sealed with a good adhesive caulk) if you plan on firring out your drip edge.
Hey Scott Sidler,
Thank you so much for your informative post, I am really appreciat.
I agree a 100% with you, it is a common problem. I install gutters and I see this on a regular basis. Your idea might solve the dripping issue but will create another one. Especially in the rake section of a roof where there are no gutters to hold your aluminum fascia board. By adding your furring strip you are preventing the drip edge to hold the top section of the fascia board vs the elements ie. high winds etc.
Metal expands and retracts with our lovely Canadian winters therefore accentuates the need of a snug drip edge over the fascia.
I guess in your climate you have to choose which issue you want to prevent. For me it’s still the rot issues, but I see your point Al.
You are a dick for pretending you know what you’re doing.
Grolfff, I can only assume your are either a bitter roofer who prefers to not do things the right way or a random troll with nothing better to do with your time. Either way it’s a joy to make fun of you. 😉
How do I replace the facia board without disturbing the furring strip?
Usually both will have to be replaced if your fascia needs replacement.
Great explanation of how to install a drip edge. Thanks for posting!
I am wondering how a gutter impacts the install of drip edge.
The gutter should slip behind the drip edge and shouldn’t affect proper installation of either.
Yes, nice to see someonelse notice this!
Surely you’ve made an error in your drawing where you have the roof edge installed OVER the first shingle on the ‘DO’ drawing!
The use of a small block to break capillary action between the edging and the roof is a good one.
The drawing was quick and dirty and did not include shingles. I just wanted illustrate how the drip edge should be installed. Common practice is to have the drip edge installed on top of the underlayment but below the shingles. I’m not a roofer but it would make more sense to me to have the drip edge underneath the underlayment as well.
I think that was meant to be underlayment, not a shingle. Representing an eave without the gutter and shingle shown.