How to Install Pipe Flashing on a Flat Tile Roof

In this video, I’m going to show you how to install pipe flashing for your tile roof.

Your roof is gonna have multiple different pipes and penetrations coming out from it, whether it’s for plumbing, heating, air conditioning or electrical, regardless of flashing methods are the same, as well as the different sizes, you’ll have anywhere from an inch all the way up to get eight inches of pipe flashing that you might have to install. The concept is the same, always remember to properly waterproof your underlayment as well as your tile roof. When you watch this video, I’m gonna show you a few tricks to make sure your pipe flashings never leak.

Start by installing underlayment on the wood deck. (Watch the above video at 0:29 to see how that’s done.)

Install Pipe Flashing Over Underlayment

Now that we’ve got our base layer installed, what we actually wanna do is install a piece of pipe flashing around these pipes. We wanna do that around all our penetrations. Essentially, the idea is that our underlayment needs to be a 100% waterproof. So if we were not to install tile on our underlayment, we would still not have any leaks regardless of how strong of a rain we had. So the way we wanna do it, is first off, just install this pipe flashing. Now, we wanna nail it. We’re gonna be nailing it just like any other flashing. We don’t want to put any nails on the bottom side here. Now, it’s still not done with this process. What we wanna do is actually install a piece of underlayment on top of this in order to make sure that there’s no water that comes in on this top edge right here. You can see if water were to come and roll down here, it would get underneath here and cause a leak. So we wanna install a piece right here before installing our top layer to make sure that this is a 100% waterproof. So Marco has already cut this out for us. And the width of it is not as crucial.

Prime the Flashing

Now, before we actually install this, what we want to do is prime our metal. I’m not gonna fully prime it, but you’re pretty much using an asphalt primer, both on your flashing and on your underlayment. You can also do it on your wood deck. What this does is really provides a very solid bond between your self-adhered underlayment and your flashing. Once the primer is dry, we’re ready to install the second piece of flashing. We just wanna align it on top and now start cutting out the opening. Cut the underlayment wide, leaving about one inch exposed.¬†There’s two reasons for this, number one is to allow water to properly flow and give a path for the water to come down. Second of all, once we install our tile, our tile’s not gonna be butted up tight against this. It’s gonna be set back a little bit so that once we have our tile, it’s not gonna be visible from the exterior. So we have this cut already. We just have to remove our adhesive backing. With just a few seconds, I’m already having a hard time pulling this off. So again, once the sun heats this up, this is gonna be solid, definitely not gonna leak. And with this piece of underlayment installed, there’s no way this pipe’s gonna leak. Even if you don’t have tiles installed, this is gonna be completely waterproof.

How to Measure, Cut and Install Tiles Around Pipe Penetrations

Now, we’re at the point where we’re getting to our pipe and we’ve gotta install our tile. Now, the pipe is in our way. What we’re gonna do is, we’re gonna mark it out, again, just as always, you can use your measuring tape to measure this distance. I always like to put the tile up against the pipe flashing and actually make my mark right here. And we’re gonna do that on both sides. We’re gonna line it to the top chalk line that we have set out. Now, this cut is not extremely important. We can go a little bit larger as it’s gonna be covered by the pipe flashing. As you can see, we’re not gonna put a nail right here. We don’t want to get a nail too close to this flashing. We want to nail a little farther out. Now, we’ve gotta install one more tile here on this side and we’ll probably have to make a light notch on it. So we’re bringing our tile here. I’m gonna use this as a reference point on where to cut. And we just literally need about 1/2 inch off that tile right there.

Install Secondary Flashing Over the Tiles

Now that we’ve got these tiles installed, we’re ready to install our second pipe flashing. Remember we have our primary down with our underlayment. We’re gonna be installing our second layer of pipe flashing right here. One thing we like to do, is just for aesthetics. We like to round these corners off. Again, you don’t have to do this at all by any means. We just like to do it. And I think looks a little nicer, look a little cleaner on the roof. We wanna prime it and paint it prior to the installation on the roof. And if you also get a chance, etching it with vinegar also helps adhesion of the paint.

This is something you can always do after the fact, but it just makes it a lot easier and a lot cleaner so you’re not worried about painting your tiles accidentally. Doing it previously just makes your job go easier and gives you a better finished product. Now, we’re ready to slide this pipe flashing right on. And there you have it. You really don’t even have to put nails back here. We definitely don’t want any nails here in the front. When we install the next row of tiles, that’s what’s really gonna hold it down and make sure the wind doesn’t lift it up.

Cutting & Installing Tiles Over and Around the Pipe

Now, this next tile is a trickier tile. This is a tile that has to be cut in the correct shape, and it’s gonna fit snugly around here. Again, you don’t have to worry about getting too tight. We can leave about 1/2 inch to an inch space between the pipe flashing and the tile itself. So we just want to put it in place right now and make our marks. What I like to do is align the tile, then use a piece of flashing, really we’re just using this as a ruler. I’m gonna do that on both sides here. Now, in order to get my depth, what I’m gonna do is use the tape measure from the bottom of this tile to the bottom of this. So I’ve got 5 1/2 inches. I’m gonna give an inch extra. So we’re gonna cut this at 6 1/2 inches high. We’re marking at 6 1/2 right there.

Again, there’s not gonna be a perfect cut and does not need to be either. Then I’m also gonna go 1/2 inch to 3/4 inch wider than the pipe flashing itself. We’ve got this tile cut already and we’re just gonna pop it in place. You can see that the opening is larger than this pipe flashing, but that’s totally fine because any water that’s gonna get on here is gonna easily drip down. So unless it’s a very visible area, you can work on making this a cleaner and tighter finish, but if it’s not visible like most pipe flashings are not, you can just do this however large you want. And really you’re ready to continue with the rest of your roof and move forward. One tip that I like, and one thing that we like to do is at this point, while we’re working here is actually caulking this joint with a metal adhesive and painting it just so that we don’t have to come back and walk on the tile later, since tiles tend to break and it’s hard to walk on, we don’t wanna open up more work, so while we’re here, we generally caulk this, paint it, and call it a day.