S01E01 - Drip Edge Wisdom: The Moose's Tale About Defeating Water Intrusion

Transcript

Welcome to Moose Tales. I'm Jon with Two Moose Home Inspections, and I have some short home inspection topics that I need to get off my chest. So, let's dive right in

as a home inspector. One of the things that we see quite a lot is that flashing details just are never done correctly. And so, what is flashing? Let's first start there. Basically, you can think of flashing as a piece of metal or some other waterproof object or thing that prevents water from going somewhere that you don't want it to go.

Or once water has gotten somewhere that you don't want it to be. It causes the water to go somewhere else. And so, when we talk about flashing, it should be one of those details that whoever is installing the roof, installing the window, installing the deck, installing doors, they should know what flashing is and they should know how flashing should be installed.

let's talk about

cohesion, adhesion and also the capillary effect. And so, we're action, capillary action. And so, if we're talking about that, cohesion means the ability for water to stick to itself. If we're talking about adhesion, that is the ability for water to stick to things that are not water.

And then if we're talking about capillary action, that is the ability of water to move upward against gravity, to go somewhere unintended. And so, when we talk about that, one of the easiest types of flashing that most everybody is aware of is what's called drip edge flashing. Now, imagine that water is rolling down the slope of your roof, and whenever it gets to the end of the roof, a lot of us would just think, the water just goes right off the end and that's that lands on the ground, everything's good.

Then we can talk about slope and grading and a whole bunch of other things that may lead to water intrusion. You know, in your crawl space or basement or whatever it may be. But we're not going there. All that we want to talk about is, is it actually getting off the roof the way that you want it to?

And the answer is no. A lot of times it doesn't because of adhesion, what will happen is the water is going to stick to that roof shingle. It's going to make it to the edge of that roof shingle and then it's just going to keep sticking. And then it's just going to be resting on the bottom side of that shingle.

Now, because of cohesion. More and more and more water is going to go there and stick whatever it sticks. Well, where is it going to go next? There is the possibility that if you have old shingles, if you don't have proper underlayment and a whole bunch of other issues, that you could have capillary action taking that water elsewhere.

But the main thing is, is that we have something installed called drip edge flashing. That drip edge flashing is going to take that water and it's going to say, hey, come with me and we're going to bring you down around the fascia board and we're going to have you drip right off the end. Now, how does that happen?

Well, the idea is, is that that drip edge flashing should be separated anywhere between quarter and half an inch away from that fascia board. Now, fascia board is the part of the roof directly underneath the shingles that you can see. It's normally like six inches wide and it's normally painted whatever color, you know, the accent trim for the house would be painted.

And so that right there would be your fascia port. So, if we were looking at a house, the raindrops are rolling down the roof towards us. It gets to the end of the shingle. It says, I'm going to hang on to this for just a little bit because of adhesion, then because of cohesion, we're going to get a whole bunch of other raindrops accumulating in that area.

And then the drip edge is going to say, you know, why don't you just come with me and then you're allowed to go and drip off the drip edge. And how that works is the drip edge is a piece of metal, and the metal will have like a little bit of a kick out at the very bottom of it, because we know that the water is going to come down, stick on the bottom, kind of go up backwards a little bit, and then finally settle all the way down.

And whenever enough water has gathered, it'll drip off and that trip edges good to go. The problem with this is that so many times this detail of flashing is just completely misunderstood, and mis installed. And so, a lot of times we'll see that there is no gap or spacing between the drip edge and the fascia board. So now what happens is the water comes down that drip edge, it makes it to the bottom, kind of slingshots around to the backside and up.

Now it's in contact with the fascia board. And because of that, we now have rotted damaged fascia, and we have to either repaint the house more frequently, we have to replace pieces of wood, or we have water intrusion into the house, depending on the roof detail. And so that should be a pretty easy thing to fix. You can just kind of, you know, bend out that drip edge and make it a little bit better.

But rarely does that ever happen. So, then we get to the corners of that trap edge, and so many times it's improperly installed the way in which they overlap it, the way in which they cut and bend. And then that obviously doesn't give you the kind of protection that you actually need just cutting corners to make things install more quickly.

How do we integrate our drip edge with the underlayment? That's a whole other topic for discussion. And so there are so many opportunities for this drip edge to work appropriately and well. It just doesn't. So, another place is what's called kick out flushing. Let's say that you have a wall, and your roof comes down and you want all the water to drip right off the roof.

So again, we're looking at the house, the rain is coming towards us and there is a wall going forward and back away from us. And then there, of course, is the roof that is coming towards us. Now, all the water in the center of the roof and on the other side is going to drip right off. That's great.

But the water closest to this wall that is coming towards and away from us, what's going to happen with that is that the water is going to stick to that wall. And what we're going to see is that we're going to have rat issues, mold, mildew, you know, algae growth, whatever it may be, all kinds of issues, deterioration of materials.

And what should have been installed is something called kick flashing. And that kick flashing should be pushing that water and all that. It is. Imagine if you were to just take your hand and put it underneath the faucet at like a 40-degree angle and you are diverting that water elsewhere. Whenever you put your hand underneath the faucet instead of allowing it to drop straight down, your kind of saying, go over here just a little bit.

That's what kick out. Flushing is so many times kick out, flashing is missed, and it's just one of those super easy things. Now, what's before the kick out flashing on that wall? It's something called step flashing. And now the way that step flashing works is that we have a shingle and then we have a piece of metal, and that metal is basically in the shape of a letter.

L extrude it out, you know, the length of the shingle. And so basically what we have is imagine if I had a single shingle again, looking at the house, looking at the shingle, the water would be coming down towards me. And let's just imagine that on the side of that shingle underneath the shingle, we have four inches of metal that is then bent and is now going vertical.

So, it comes four inches from underneath the shingle and then goes four inches high to the side of the shingle. And this little piece of bent, you know, just ten metal, whatever it may be. That right there is what is preventing any water from hitting and going into the wall. And so, what happens is water is going to use this step flashing water is going to find its way over to that wall.

And instead of going in and underneath the wall and damaging materials, we now have this metal flashing that is protecting this. And so now what happens is, is that the water goes, it hits the metal flashing and its step flashing. So, what happens is that the next course of shingles, the next line of shingles, the water comes out on top of that line of shingles, because that's all the longer that that piece of step flashing is.

But what's underneath that next course, another piece of flashing and what's underneath the next course, another piece of flashing. And so, as we work down that exterior wall on the edge of our roof, we have step flashing. We have little pieces of metal that are bent to a 90-degree angle that are just working their way down, and they're the same width as what we would say.

The shingle is each course. And so, what that flashing does is that every course of the shingles water is given the opportunity to come back out onto the roof. What has happened is I have been an expert witness in a case, and they wanted to use continuous flashing. The problem with continuous flashing. If we're going to talk about adhesion, cohesion and also capillary action, the problem with a single piece of 90 degree bent piece of metal as a single continuous flashing is, is that we know that water is going to get underneath that flashing.

We I mean, we know that water is going to get our neath the shingle on that edge and we're going to rely on that flashing to get the water where we want it to go. But every 6 to 8 inches, depending on the size of that shingle, we are missing an opportunity to pop back out onto the roof and for the water to be properly evacuated off of the roof.

And so, with that continuous flashing, what will happen is, is that we are then going to get a buildup of water. That's going to be our cohesion. We're going to get adhesion where each shingle is an opportunity or a point where the water could say, I'm going to stop here because we have a new course, a shingle.

So that's like basically like putting a new dam in the river and the water has the choice of do I want to slowly trickle underneath the shingle or do I just want to go left or right, whatever direction it may be based off of where you're Wally's, which would then mean the only thing protecting your house from a leak would be the underlayment.

And is the underlayment good enough to not only prevent that leak, but to get the water all the way down until we get to that drip edge. And then is that drip edge good enough to be able to get the water on to the ground? And so there are so many details that we see that if you just put your mind in the place of if I was water, where would I go?

Where would I have the least, you know, resistance? You're going to be just fine installing roofs. But if you just say, how am I to get how am I going to get this job done more quickly, then there's just no way you're not going to do the detail correctly. And another thing is, is that whenever you look at something like Owens Corning or, you know, whatever roofing company you look at, they say, 30-year guarantee, that's great.

But here's a deal for a 30-year guarantee, you have to use their underlayment, their shingles. They're flashing every aspect of that. You have to be licensed by them to install with that guarantee, and you have to have a certain number of roofs that are installed, inspected by whatever company is offering that guarantee. And if you miss any of those steps.

And also, you as the installer are going to be the one who is filling out all the documentation for that warranty and getting that pre-approved for the customer. And so if you miss any of these steps as the builder now you have a quote, 30 year roof, but unfortunately your customer has no guarantees, no protection, and you as the builder are now responsible whenever there is a leak to come back in a find leak, which is insane to find a leak and then B, to repair the leak.

And sometimes there's so many problems that you kind of need to just start from scratch. So, we see issues overtop of windows. We see issues over top of doors, because if we have moisture that comes in and it gets past the siding material, it's going to. So, when it gets past that siding material, we need it to come out before it gets to the seam of the window, which would allow the water to then come into the house.

And we need it too, we need the water to come out before it reaches the seam of the doorway and then comes into the house. And so, with all of those things around the doors, around the windows, we need to have really good flashing details. Think of it like this. If we have the letter you, then what will happen is, is that if I filled up, you know, in two dimensions, if I filled up that letter, you then that letter you are going to fill up with water.

If I have the letter N even if some water got into the center of the letter and the letter and is not going to hold on to any of that water, that's the way that we want to think about our flashing is then if we do get something at the base of the letter n, how do we get that out and away from that particular letter?

Or in this case, how do I get that out and away from the door? Do I have flashing on top? Do I flashing on the bottom? What are my details on the sides? That's a lot of things that end up getting missed. Additionally, whenever we talk about debt construction, the ledger board that attaches to the house the way that that ledger board attaches to the house, we need to have flashing that is taking water away from that connection point because if water gets in between the actual house, the structure of the house and that ledger board, well, what's going to happen is we're going to have a lot of high levels of moisture, which

is going to then lead to rot because, you know, different fungus, whatever is going to start eating away at that ledger board. And then we have decks that can separate from houses and end up killing people. And that's just obviously not ideal. So sometimes another type of flashing that gets overlooked is flashing on the top of a chimney.

Now, on top of a chimney, what you should have done is you should have some kind of a cap. That cap could be made out of a stone or brick. It could be made out of metal, it could be an asphalt cap, it could be many things. But I'll tell you what, it should not be should not be Grace, you know, ice and water shield, whatever underlayment that you have, that is not acceptable for mechanical damage.

Not acceptable in mechanical meaning, like some something is hitting it, stepping on it, you know, birds landing on it, whatever it may be, and is also not designed for any kind of protection from UV radiation and deterioration. And so, whenever we see houses that they just put, you know, that underlayment on there, that is completely insufficient and you're going to have a leak from the top of your chimney.

So, you need to make sure that the cap, which is a type of flashing, is also done correctly. Now, there are so many other things that you can do, like, for instance, on a deck, you can actually have each joist have like a tape applied flashing that basically prevents the water that's trapped between the joists, the floor. JOYCE The going provide the support, you know, across the deck and then the decking, which is the material that you're actually walking on where those two products intersect, what you can have is you can end up having, again, water trapped in that area.

And if you know, like if it's predictable, then it's preventable. And so if you know the water is going to be trapped there and, you know, that's an area that normally rots, then what I would say is it is in your best interests to just go right ahead and put down some tape, you know, applied flashing material. And then that way you don't have any issues with rot on your particular deck build.

And then the last thing that I want to say is think about where water goes and when water goes to those places. Because in our area, we also have a huge issue with heat loss through people's houses, mostly because we don't control air movement inside of houses. But anyway, we get heat loss that then heats up the roof, the roof then moves down and melts off a whole bunch of snow, which comes down to the eaves.

The eaves are not heated because they're extended over the house and then we get ice dams. And in those ice dams, if I'm now telling the water, hey, you're going to just stop here behind this dam and we're actually going to back up maybe two, three, four feet and we're going to be holding on to all of that water.

How do our flashing details act in those situations? Do they act properly? Are our flashing details high enough? Do we have the right materials underneath the siding, the right materials underneath the shingles to be able to make sure that whenever we do have an ice dam, which are avoidable, but not with the type of houses that we typically inspect because taking care of ice dams and the ideas behind how ice dams are prevented is more or less new on the building science side of things, which comes down to like tighter houses, better insulation, better R-value and a whole bunch of other things about orientation of roofs to get direct sunlight, yada yada yada.

Anyway, most traditional houses are going to have ice dam issues. It's just the nature of things. So how are your flashing details going to operate in those situations? Additionally, if we think about like our kick out flashing, how is our kickoff flashing going to act whenever we have the force of an ice dam pushing with glacial force down that roof?

Is that kick out flashing going to survive? Is it robust enough? And so those are a lot of considerations that need to be made. Long story short, I guess I'm not really offering any suggestions on how to fix this stuff. I'm basically just saying if you have a house and it has a roof, your flashing details are probably incorrect.

And I would recommend checking owners sorry, the manufacturers manuals on how these things are supposed to be installed. Now, if you're not having a problem, is it a problem? Not really. But if it's predictable, it's preventable. So that means that we can say it's probable that something like this is going to happen. And so, let's just call this out so that way we can make a decision based off of our risk assessment, meaning you as the homeowner, like your own personal how adverse are you to risk?

And then you can make a decision of whether you want to be repaired, replaced, or you're just going to keep on going with it, just as it has been for the last 20 years. Anyway, that's everything I have got to say about flashing for the moment. That's a pod.

Thanks for listening to Moose Tales. This short home inspection topic was brought to you by Two Moose Home Inspections and was intended for entertainment purposes only. Keep putting one hoof in front of the other and keep those ears perked up for the next episode.

Thanks again.