Drip Edge Overlap

Here we have the south side of the house.* I count 4 layers of rolled roofing...and probably 2 layers of felt paper. The top layer of roofing has almost no adhesive bonding it to the layer underneath, but the top layer is in OK condition except for some blistering caused by the fact no adhesive was used and it wrinkled. Any issues with this roof are not because of old surface roofing. 

The photo above shows the ridiculous method previously used of wrapping a piece of wood in the edge of the roofing and then nailing it to the fascia. I could tell how well that worked when the wood turned to dust as I broke it away. Now, to be fair, the roof was installed when Jesus was a Corporal, so hey, that's a long time. Nothing lasts forever but this method doesn't meet my high standards so I'm going in a different direction.

Here's what it looks like after I tore the old edge off.

I started thinking, which is bad enough, then I started watching DIY videos which is worse. I had a goal to work purely from instinct but my instinct is to look for example videos of how other people have done these kinds of repairs. Basically, no repair I'm attempting is the first of its kind, but all the repairs I'm doing are because someone failed in their attempt to repair it. Is the person who wrapped the asphalt paper in a circle around some wood waiting out there for me to call them? Probably they are long dead.

DIY projects invariably decay into a series of experiments that take a long time to get results back. So long, sometimes, that the person has sold the house and the new owner thinks the experiment was a bad attempt. Maybe, and maybe not. Maybe it was an experiment like the ones I'm doing.

The specific issue I'm dealing with is rolled asphalt roofing. This is sort of the same material as basic asphalt shingles, except it's a 3' x 35' shingle. Owens Corning has this PDF for my examination and enjoyment.

It is all right there in plain English (and Spanish) and even a diagram. There are no nails at the bottom of the roll near the eave. That's an interesting detail because all of the eaves that I'm repairing have nails in the edge. I think that's because there is no asphalt adhesive used. Ok, so that's the detail I'm puzzling about. Asphalt adhesive is the product to use to bond the top layer of roofing to a 9'' strip that has been nailed on the eave. In my specific house there were 4 layers of rolled roofing both adhered with cement and also nailed. So, the next person was thinking, what's the point in using adhesive to glue the 5th layer to the 4th layer. Maybe they have a point. A nail secured the roofing to the next lower layers. Now, some of the nails were actually too short to penetrate to the wood deck, but let's forgive them for that detail. They were attempting to fasten the top layer to the bottom layers and the bottom layers were secured to the deck, so in theory they were trying to do the right thing. And they saved a few bucks in the process by ignoring roofing asphalt.

Now, the big issue that I'm looking into is how to add a proper drip edge to the eave...that has never had a drip edge. Ideally, in a perfect world, I would get down to the wood deck and slip the drip edge underneath all those layers of rolled roofing and tar felt. But in this reality there are hundreds of nails and asphalt cement bonding this huge tar sandwich to the deck. What to do? Well, I slipped the drip edge into the one place it would go, under the top layer of roofing and the next layer under it. Then I nailed it down and smeared some asphalt adhesive under it too.

Here's a literary illustration of what I've done.

TOP LAYER ROOFING

----------------------------------

DRIP EDGE

..............................................

THICK LAYER OF 4 Layers of OLD ROOFING

==================================

==================================

Wood Decking

_________________________________________

Now, drip edge should be installed immediately over wood decking. And to do that I should tear up the mess that exists at the eaves of this roof. The extent of this project is not so vast that I don't have time to do it. I could probably demolish the entire roof in one day. But, what's the objective? The theory is that the drip edge should be the last line of defense for water that is running down the wood deck. But the deck in this case are horizontal boards with hundreds of holes in them and gaps between them. In short, no water is ever going to run down the wood from any leak and get to the drip edge. No, the water will run inside a gap or nail hole and drop onto the other roof under this roof. So, the drip edges I'm adding are purely for one purpose...to direct water running off the top layer of roofing away from the house wall. Any leaks or other problems will not involve this drip edge no matter where I put it. There are so many layers of roofing and it's all asphalted together that there's no way to 'do it right' because I could only break everything down and start from scratch, which I'm not going to do.

So, I'm back to doing the best I can to add a drip edge with the only goal of improving the water shedding at the eave. yes, water from a leak will theoretically go UNDER the drip edge if it makes it to the eave but I don't see how the water can possibly reach the eave if it's going over hundreds of holes and gaps in the wood deck. If you think about the wood deck of a roof you imagine a smooth, nearly water resistant surface. Well, that's before you nailed thousands of nails and staples in it. Yes, water will leak behind the roof surface eventually, but the videos of roof leaks rarely involve someone saying "See, if this drip edge had been properly installed under the felt paper then the water would not have been trapped at this point an inch above the drip edge. " 

No, the leak immediately finds a way into the attic. The drip edge does one job: shed water from the top layer of roofing. Sure, install it directly onto the deck. Why not? But don't delude yourself that a leak under the roofing material and the underlayment to the deck and will run all the way past a hundred holes and gaps in the decking until it finally gets trapped at the point where the drip edge was nailed over the underlayment. I see that happening if an entire section of roofing material was torn off and water poured in from a hurricane directly onto the wood deck where it ran under torn roofing and tar paper. Sure. But a little leak that reaches the felt paper will go to the nearest nail or staple hole and go right through to the attic underneath the roof deck. The drip edge placement is best directly on the wood deck of the eave. But in my case when there are 4 layers of roofing material nailed to the roof, then the second best place is beneath the top layer of roofing.

This brings me to another issue I'm pondering: The prevailing wind rake. 

The 'rake' is the part of the roof that is sloped.

here is the prevailing wind rake of my house. The abuse is evident.

here is the non-prevailing wind side of the house. This is the 'Lee' side of the house. It doesn't show as much abuse.

I got a better photo of the Lee side of the house so let's use that as an example. Imagine this were the windward side. Now, the same method of rolling the roofing material around a piece of wood and nailing it into the house was used here and it's all decayed and ruined so I'll be adding a drip edge around the entire house if everything goes well and I figure out a method. The experiment I want to try is to focus on the windward side of the house which is a rake. The leeward rake needs a drip edge but little water probably sheds from this side so it's not a huge priority. The winds here are strong and the windward side of the house gets a good burst of wind...when it rains the water pounds this one side of the house almost horizontally. Now, WHY would I follow the directions and install the drip edge under the rolled roofing and over the tar paper? Why do that? That will create an edge, that is nailed down and adhered with cement to the drip edge. Why not, on the prevailing wind side of the rake, staple and use cement to fix the tar paper to the wood deck. Then use adhesive to fix the roofing to the tar paper. THEN install the drip edge over everything and lay a good bead of cement under the drip edge before nailing it down good and tight. Yes, the surface of rolled roofing is not as flat as wood so there would be some rolling in the edge, but the layer of cement or butyl tape under the rake drip edge would seal those small imperfections. Then...when the wind blows water against the rake...the first and only thing it hits is indestructible galvanized drip edge. There is no lip of asphalt or tar paper or nails to loosen.

My visualization of this scenario has me hearing a voice of experience saying, "Oggy, a properly adhered underlayment with a concealed nail method...a 9'' strip of roofing material nailed over tar paper that has been cemented to a properly primed drip edge on the rake will create the same impenetrable seam that you are trying to create with a drip edge nailed over the entire edge...plus, any repairs to the roof will now involve removing the whole drip edge and risk damaging it...when you normally don't have to touch the drip edge to replace the roofing material since it is installed under the top layer."

I hear this voice of experience and answer: Ok, you think you're so smart. Why not DO BOTH? Huh? Why not cement the tar paper to the deck. Then nail the primed drip edge over the tar paper. Then nail the starter strip of roofing material to the drip edge using asphalt cement. THEN, once you have confirmed the asphalt sandwich you have created is solid, THEN add an additional drip edge that is shorter than the drip edge below it. Then you have triple protection on the windward rake! I'm not talking about doing some insane experiment around the entire roof. No, I'm focusing only on the windward rake that takes the most abuse. Why not use everything under the sun to keep water out of that area? Kind of like my plan to cover this roof with a metal roof. But this roof is already covering another roof. And this roof is made of 4 different layers of roofing. So, if the original roof includes 3 layers of roofing...and this roof includes 5 layers of roofing and I add one more layer of metal roofing...THEN THAT MAKES 9 (NINE) ROOFS over one house. Again, the problem with water infiltration are not the roof....the problem is the cracks in the stucco and the rakes and eaves allowing water to run under the roof along with the Vigas directing water back into the house.

here's another written illustration

_______________(top drip edge nailed to....

|    Top Layer Asphalt Roofing

|    cemented layer of felt

|     felt cemented to primed drip edge

|    _______________ (bottom primed drip edge nailed to....

|     |

|     |   WOOD DECKING

     |

     /

It's possible someone might say, "Oggy, what you're describing won't look good." So I include this photo from my roof. Does this look like a place that is concerned with aesthetics? We have literally rusting metal roofs...decaying fences...a huge pile of arsenic laced, rust colored, lead rich soil surrounding the town. The alley is unpaved. Dogs run freely. This is a town for practical people. All that matters is keeping the rainwater out of the house. If you can do that then you have succeeded.

*I'm tempted to make a video showing how I approach this but that might trick some innocent viewer into thinking I am trying to train others. No, that is not what this blog is for. I'm only trying to record my process of DIY thought. Training is not done on videos. We aren't in the fucking Matrix where you click "Download" on a "How to be a roofer" file. No. In the real world it takes years to learn the finesse involved with each process, let alone the decades to learn the insane number of products one can use. Have you seen the caulking aisle in the hardware store? It's insane. Many ways to get the wrong item. It's like going to the store and accidentally buying "Low Fat" cream cheese...as though a person eating cream cheese is counting calories for fuck sake! Well, you go to the cereal aisle and accidentally get a frosted flake you didn't intend to buy....and you're going to eat it. I'm sure you will. Because it's all the same cereal. Well, you're fucked if you get the wrong caulking and still use it. This is just an example of the infinite combinations of the wrong material you can purchase that will cause a huge mess and make you look like an asshole. The difference between Cement and Adhesive is pretty significant although any innocent person would think they are the same thing. Cement patches holes when used with fabric....Adhesive binds two new surfaces. In short, don't think I'm training anyone about these topics. I'm a philosopher, not a roofer. The process and underlying principles are important because the roof and my flesh and blood are all going to be wearing a wood suit one day. The principles will remain.