How to Install T-top Flashing On A Roof With Flat Tiles

What Is T-Top Flashing?

T-tops are used to exhaust different types of air from your attic, whether it’s a bathroom fan, kitchen fan, any type of exhaust, laundry or anything like that, any type of air that’s flowing out, a t-top is used. Now any tile roof, it’s important to remember that you need to install two layers of flashing. So underneath the four inch t-top, we’re gonna be installing a four inch pipe flashing to ensure that the underlayment is just as waterproof as the tile on top. Now, depending on what type and what size t-top you use, that’s gonna determine the size of your pipe flashing. So if you’re doing a kitchen vent, you might be using a seven inch t-top, we recommend using a seven inch pipe flashing. But the concept remains the same, make sure that your underlayment is waterproof, then move on to your tiles.

Cut Out Your Vent Opening

Now we don’t have an actual vent in this mock roof that we have built, but I’m gonna assume that we have an opening right here. So I’m just gonna cut where our vent is gonna be. And a lot of times our four inch pipe flashings or our four inch t-tops are gonna be used when we have bathroom or kitchen exhaust fans. So we’re gonna assume this is our exhaust fan right here.

Install a Pipe Flashing Over the Newly Cut Opening

Now the first thing we do before we get installing a t-top is installing a pipe flashing. You might be wondering why. The reason for this is simple, just like in anything else in tile, we wanna make sure that our underlayment is a hundred percent waterproof. So if water were to get behind and underneath our t-top, we wanna make sure that we have this pipe flashing in place and it can exhaust from here. So, pretty much what we’re gonna do is install the t-top on top of this. So if we have this right here, we’re gonna flash this in, then with our tile we’re gonna install our t-top here. So if there were any water to get behind here, it would be flowing around here, but our t-top will still be protecting the top of this cover.

Now, since we’re using a self adhere underlayment, the first thing we wanna do is nail this down. After we tack it down, we’re gonna prime it and install new underlayment on top. Again, primer is something that we recommend for any time we’re installing underlayment, especially on top of metal. It really helps for a good adhesion.

Install a Layer of Underlayment Over the Base Flashing

Now that our primer has dried, we’re ready to install a layer of underlayment on top of this. You can see, we made about an inch space between the underlayment and the pipe flashing. The reason for this is first of all, we wanna allow a channel for the water to flow down. Second of all, when we install our tile, it’s gonna be a little wider than the flashing itself. So we don’t want the underlayment really exposed to the weather. Now we’re just ready to peel that adhesive backing off and lay this down. Now this is solid and bulletproof and there’s no way this will leak.

Always remember the idea of any tile installation is, regardless of how much water comes from on top (’cause water does get underneath the tile), it’s not gonna leak; it’s gonna come on top of this underlayment, on top of this flashing, then off our roof.

So we’ve got this done, we’re ready to install the next row of tiles and start cutting around our pipe flashing that we have, then we’re gonna install the t-top after that.

Cutting & Installing Tiles Around a Pipe Penetration

Now we’re getting up to our pipe flashing. What I like to do is align the tile that we need to install and just mark it out. Really this is just gonna require a small slit. Now what I actually wanna do is cut out the entire lip. Let’s mark the entire thing. Let’s say till here. So I just need to cut this lip off right here and we can install this piece. Alright, now we’re ready to install our next tile. Again, I’m gonna just align it where it should be. So I’ve got that mark right here. I’m also referencing my chalk line that I have. Want to mark at the bottom of this. That’s what I wanna cut out.

Install T-Top Flashing On Roof Tiles

Alright, now that we’ve got our row installed, we’re ready to install our t-top. If you watched our other videos, you know we always like to round off the bottom of our flashing. This is just purely, especially on tile roof, for aesthetic purposes. On torch down and shingle, it does serve a purpose not to puncture, but in this case, we’re just gonna round it off. I think this looks a lot cleaner and nicer. And another thing we would do, if this was an actual project, we would prime and paint this t-top prior to installation. It’s a lot easier to do it when you’re off the roof, you can get a lot better coverage of paint instead of trying to cover the roof. But again, for this video, we’re not gonna do that, but it always makes it easier. Prime and paint all your flashings prior to starting your roofing project, it’ll just make the project go smoother and give you a better finished product.

So assuming that this was painted already, we’ve already got our four inch flashing, we’re just gonna pop this over it and we’re ready to install the next row of tiles. And we’re not really worried about nailing this down. We could just put two nails down here. Another thing we can do is just put a little bit of mastic down here in order to get this adhered down. But once we put our next row of tiles, it’s really gonna hold this down and this thing’s not gonna go anywhere. But again, if this was a real project, I would recommend putting a few nails up here, as well as getting mastic under here to adhere down to the tiles. We’re now ready to start cutting our tile and getting it in place. I like to use either an old piece of flashing or a ruler, really whatever it is that I can use to give me a straight line. I’m gonna give myself an additional three quarters of an inch or so on this side and mark the width. Next thing I’m gonna do is align it that way and mark the height. Now I just need to square these two off.

Alright, we’ve got our first tile in place, we’re ready to mark out and cut our second piece. Again I’m gonna use the same technique – lining it up, using a piece of flashing to mark out my width. I’m gonna give myself a little bit bigger on each side to allow for proper drainage. Alright, we’re ready to pop this in place and call this a day. There you have it. Our t-top is all completed. Now you might have noticed the uglier cuts around this flashing. That really doesn’t matter unless it’s super visible from a second story window or something like that. Really, for waterproofing purposes, this is gonna do perfectly well. These cuts have nothing to do with it, it’s gonna drop on the flashing and roll off our roof. Always remember any time you’re doing anything in tile, you always wanna make sure that your base layer, your underlayment is completely waterproofed. This is really just a secondary layer right here. So this is what a property t-top flashing looks like and it’s gonna last the customer years to come.