Installing a Ridge Vent on a Shingle Roof
What is a ridge vent?
In this video, I’m gonna show you how to properly install ridge vents on your shingle roof. Ridge vents have been used for the last 10 to 15 years on shingle roofs and I think that they’re a great addition to a venting system if done properly. Now, ridge vents are an exhaust. If using ridge vents, you have to make sure that you properly calculate intake so that you can exhaust in the correct proportions. I’ll make a video separately on that, you can watch that about properly venting your roof and doing the right calculations. For now, we’re gonna show you how to install ridge vents.
In this video we’re gonna be using Owens Corning VentSure Ridge Vents, they come in rolls. Now there’s a bunch of different shapes, sizes, different manufacturers, but the concept kinda remains the same throughout all. We always recommend using the same venting system or the same venting material as your shingles. So, since we’re Owens Corning Platinum Contractors, we like to use Owens Corning VentSure strips.
This is a close-up of how it looks. Essentially, this can be bent to any degree. So regardless of how steep your roof is, you can use these Ridge Vents. They have this protective mesh that we really like. This ensures termites, ants, any type of bug is not able to get through this. However, it’s still able to vent properly. The end is just a corrugated plastic, similar to cardboard, but in a hard plastic, so that once you nail through it, you can drive nails easily, and install your ridge caps on top. So the way these work is, you install this ridge vent and then install the ridge cap on top of it.
Here’s a small demo that we have. The nice thing about ridge vent is, it allows the hot air (since hot air rises in your attic) to exit, without baking your Ridge caps. So it’ll have a slit cut from underneath to allow the air to exhaust out and essentially, the hot air will come here and out these sides.
Ridge vents are great. We definitely like using them. However, there’s a few important steps you have to make sure that you follow to make sure that not only does it vent properly, but more importantly, that it stays waterproof for years to come.
How to measure and cut your vent opening
The first thing we wanna do is cut our sheeting to ensure that we have our strip that is gonna allow the proper airflow. Now, this kinda depends on what kinda framing you have. If you have a trust framing, meaning you don’t have a ridge board, you’re just gonna cut a two-inch slit for one inch on each side. If you do have a ridge board, you’ve gotta figure out the thickness of that ridge board and get one inch past each side of the ridge board.
Now, we’ve got a 2×8 or a two by ridge board, so we’re pretty much gonna say that we’re gonna cut three quarters, which is gonna get us to the ridge board, an inch past that. So we’re gonna cut an inch and three quarters on each side. And I’m gonna over-shoot and say two inches just to make sure we don’t inhibit our proper airflow. The other thing that we wanna make sure is, if your roof has an overhang, you don’t wanna cut the strip all the way to the end. You wanna figure out where your attic starts and cut from that point. So we’ve measured our overhang to be 12 inches. We’re gonna measure from there, chalk a line all the way, cut that out, we’re gonna cut our underlayment, cut our sheeting, then install our shingles all the way up to it.
Install shingles up to the vent opening
Alright, we’ve got our slit cut out. As you can see, we’ve passed the one inch mark on each side of the ridge board. So again, just remember, the ridge vents are only as effective as this slot right here. You can install a ridge vent without this slot, and it will do absolutely nothing for you. So we’ve got this cut out, the next thing we’re gonna do is install our shingles all the way up to this point. Now, for this demonstration, we’re just gonna install maybe a row or two, just as an example. But you wanna make sure that your exposure point is past this area right here. So you wanna come down an inch. That’s approximately two inches down is where you are gonna have your shingles exposed. So we’re gonna install our shingles, then we will start actually installing our ridge vents.
Now that we’ve got our shingle installed, we’re ready to actually install our ridge vent. Now you’ll notice one thing, that we have brought up our shingle, and we had to cut a small little piece. That’s to ensure that we have the shingle coming all the way up to this opening right here. You wanna make sure, essentially, that when you install your ridge vent, you’re covering both sides. And then that you’re not gonna leave any part that is not supposed to be exposed, exposed to the weather.
How to prep the ridge vent for installation
Now, even though the opening starts here, we’re still gonna pass this opening, go all the way to the rake. One little important detail is these closures right here. So Owens Corning gives these, what we call end caps, for our ridge vent, and they’re actually able to separate into four. So we are just going to place this in here. Now what we wanna do is put this with some mastic and seal up those corners. Really, it’s easy to use the mastic in a tube. Any type of rubberized flashing cement will work, as opposed to getting it in a bucket. We wanna apply that liberally. Then slide this in there. And sandwich it in. You can see, essentially, we’ve sandwiched that in with mastic on all four sides. And this is gonna go on our rake end. So any time you have this end exposed, that’s when you’re gonna put this mastic.
Now we’re gonna lay that to the side for a second, and we actually wanna apply mastic around the opening. We can just start applying the mastic all the way around the edges. Now, you wanna do a quarter inch bead all the way around, including these ends right here. You wanna make sure it’s continuous. For demonstration purposes, I’m not gonna go all the way around, not to create a bigger mess.
One last thing I wanna point out is, on this side here, we’re not coming all the way to the rake, we’re ending this mastic bead right here. Pretty much, it’s around the opening that we have cut out. Now that we have that applied, we’re ready to install our ridge vent.
Nails to use for installing a ridge vent
Now, when installing ridge vents, you wanna make sure to use long enough nails to pass through your ridge vent, through your decking. Now, there’s a few ways of looking at it, but the code says an eighth of an inch past through your decking or a three quarter penetration into your decking. Either way, it ends up being the same thing, ’cause most decking is… Or sheeting is about half an inch thick. You go through about a quarter inch, so we will consider that about three-quarters of an inch. Then your ridge vent is about three-quarters of an inch too. So we like to use anywhere between an inch and a half to inch and three-quarters, roofing coil nails.
These are electro-dip galvanized. And they have a three-eighths of an inch head. That’s what you wanna use. Do not use framing nails that are not electro galvanized, and that do not have a three-eighths of an inch of a head. You don’t wanna use 8Ds, 10Ds. Use roofing nails with large heads and those are gonna do a great job for you.
How to install the ridge vent
So we wanna tack it down on one end and pull it a little bit tight. We wanna make sure we have it spread out. And for right now, we wanna put a nail in every 12 to 16 inches on center. We’re not too concerned about nailing pattern because we’re gonna install the ridge caps on top of this, and that’s really what’s gonna hold it down. When you’re nailing, you wanna nail it about a quarter to three-eighths of an inch in from the outer edge.
Alright. Now, we’re pretty much gonna install our ridge caps and call it a day. If you need an installation instructions for a ridge cap, you can watch our video specifically for that. It is pretty much the same, whether or not you have ridge vents on there. The ridge caps are gonna be installed the same. So I’m just gonna install a few just for show, or just for as an example.