Installing a Nail-Fin Window Over Zip System Sheathing

Today we're gonna be installing a flange window and a wall that already has zip system sheeting installed. The goal here is to connect the WRB of our wall to the WRB of our window to make one continuous environmental separator. The first step in that separation is we're gonna prep the sill pan below the window. To start we're gonna babble the sill. There's two different ways that we can do that. One we can use a piece of cedar beveled siding like we're gonna do here creating a positive slope to the outside. Two we could also do this in rough framing so we could add a 5 degree pitch to the outside in the rough framing sill. That will give us a positive slope to the outside and the event that we ever have Moisture. We’ll take just a couple roofing nails just something to just something to tack it into place and hold it for the moment. Now that we have this sill installed the next thing is going to be our stretch tape. For me that starts with a centerline layout and layouts up each jamb to the point that I need that tape to go. That way I don't make any mistakes on placing my tape. So I'll mark Center on the sill and then I'll mark six inches up each side. The reason I'm going six inches up each side is that gives me enough to turn the corner and it gives me a good point of reference where I'm not trying to push just a small piece of tape around the corner. I want it up high enough that I get good adhesion. Okay let's talk still pan flashing we can do this in a couple different ways the first way our preferred method is will use a stretchable tape that will flash from the sill out and onto the wall. It also will allow us to turn the corner up both sides so that we're able to go from our layout line down around and back up to our rate layout line in one piece. If you don't have the stretch tape you can go with a straight tape a straight flashing tape and you can achieve the same thing but this time you're gonna be using more pieces. Let me show you how that works. First I'm going to cut a bowtie shape piece of the flashing tape and this will be our piece that actually bridge that connection from our sill to our wall. You can notice here that I'm using the hueber family of products. Whatever manufacturer you're working with my recommendation is stick with one manufacturer that way you have one rep or one warranty to deal with if you ever have an issue. You won't run into well they're tape isn't designed to work with our system or anything of the sort. So there's our first step we're gonna flash the pan. Second we're gonna cut a V or a triangle out of both sides of this six-inch piece and then we're able to apply this so that when we turn the corner we're getting rid of a lot of that material and we've now taken care of you'll see after I put this last vertical piece on we've taken care of what would have been a pinhole gap. And now we're able to go vertically. We'll make one cut back this direction fold in now that we have these three pieces of tape in place we're managing the water at our edge. We want to take one more run of the tape in the back to protect that still as far back as we can and then the whole system will get rolled in place this is a pressure-sensitive adhesive and we need that pressure to make it adhere to our substrate. Now we're going to install my preferred method the stretch tape. We have that layout line on the center here we also have a centerline layout on our tape that centerline means that we'll end up with the same excess or the same amount after we try to turn the corners. So I like to peel the tape one side at a time. This can be a little unwieldy to do by yourself. On a larger window you certainly wouldn't try it by yourself. I'll peel this tape back we'll peel all the way down trying to keep it from sticking to itself or anything else. So now when we open up we're going to start on that centerline and we're going to start most of the way back in the in the opening and it gives us the ability to lay at each direction. Tack it temporarily over there work our way back this direction before I really make that turn. I like to take my speed square push it right into the corner so that I know that I don't have a big rounded corner. I'll push up once where to this point. I'm able to turn starting at the corner and work my way out and you may see it start to try to return to its original position but once you give it a little bit of pressure it'll stay where you want it and all we're looking for is to shed that water from the sill out and down. So same thing in this corner. I'll take my speed square, I'll create that nice square corner, I'll push it the rest of the way vertically and then starting at the corner and working my way back again I'm gonna push everything out. Once we have this tape down and where we want it we're gonna start by rolling that pressure-sensitive tape. We’ll actually wet to the surface once we have rolled the entire system. Now that our sill is installed and we've rolled it in place we're able to make a transition and work on the vertical. The vertical seam or the vertical connection from our WRB on our wall we're gonna push to the inside and connect to our rough framing. That's going to prevent any error water moving in between the connection of these two things and for that we're gonna use the seam tape. On the vertical we're still gonna overlap everything below it we're not worried about the horizontal seam that comes in here. We will be concerned with any seams on the head but we'll get we'll cover that when we get there. So to start out with I'm gonna put some layout marks because I like to work cleanly. So I'm gonna push a measurement of two inches out. The tape is the tapes three and three quarters wide. I'm also going to add a small reference mark at the top as a point for when I start this tape and that run to come down. I don't want the tape to go beyond that two inch mark and we're gonna continue and Mark both sides. Now we're ready for the tape. I won't pre-cut this because it doesn't have a backing on it. I also am a really big fan of making sure that I complete each step before I move on. So I'll get in the habit of rolling each piece of tape before I move on to the next one. Small slice here to fold in a small slice at the top to fold in. I like to press everything in place with my hand first because if you don't the tape could actually shift a little. I'll start in the middle and work my way out. It's not a major concern if the stretch tape or your sill pan tape protrudes past the the sides because they're still overlapping the correct direction. Fold that tape in everything will get some by hand pressure to make sure that it's seated in the place that I want it before I roll it. Then again everything gets pressure it's pressure sensitive tape it won't stick long-term if you don't allow it to grab by actually rolling it and you don't want to use your hand as the roller because you won't get even pressure. Now that we have our jams installed the next thing that we're gonna do is we're gonna address this head flashing. Now this is a tape that isn't required by most window manufacturers or Pella it's also not required to get your warranty from the makers of the zip system sheathing. However if we're sealing from this sheathing down to the jamb it accomplishes the same thing that we've done on the sides it stops an air leakage at that framing. There are a couple other things that we have to address while we're here because we have a vertical seam in our mock-up. We'll put our line across our layout line for our tape so that it can be nice neat and straight but here that layout line will also give us a reference for where we should cut that tape off because we want that tape to come down and lap over this in the end. So we'll cut that off or we'll peel it back and we'll have the ability for everything to shingle into place. So again we'll start with our layout marks and then I'm gonna take my knife and I'm gonna go up roughly a quarter of an inch that'll give me plenty of room to get my tape in there, get it rolled, and then when we add another piece at the end we'll be covering over that. There's one more step before that head flashing tape. We're gonna address the joint between our header and our Jack studs and we're just gonna simply put a piece of tape that turns the corner and that tape is gonna run lengthwise through the opening. When working with this stuff my favorite thing to do is lightly tack it to something and then I'm able to cut it. That way I didn't try to reel it out and keep it in my hand. So now I can take this piece, tuck it into the corner, slowly work it in so that it's straight, use my hand again to make sure I like where it's touching, and then we'll do the same thing on the other side before we move on to that head flashing. I'm gonna roll those things before I move on to the head flashing. Now I've limited the ability from air inside the opening in the corner to migrate out and in between Jack studs and king studs. The last piece of tape and I'm gonna allow that tape to fly a little pass to my vertical jams on each side ensuring that I'm covering fully. It also gives the ability to make my cut away from that piece of tape rather than here I'm out a little bit. I'm a press it in place with my hand make my vertical cuts and then fold it inward. Pressing it in place with your hand really make sure that your gonna limit the amount of air bubbles that you're trapping inside of it or just poor placement. Roll it and we're ready to unpack the window.

Now that the rough opening is flashed, it's time to install the window. The first step in installing the window is we're gonna add some shims to the sill for our sill because we have that sloped cedar. We're going to use a couple other pieces of that slope cedar. We're gonna turn around the other direction and that's going to do two things for us. First it's gonna create a level platform for our window to sit on. It's going to support the jamb coming down and then it's also going to help us center the window in the opening. If we have the window centered in the opening, we have the best opportunity to get equal insulation or air sealing around the interior side. After those cedar shims are sitting in place we'll check them with the level to make sure that we like their location and make sure that the windows gonna sit level in the opening at this time. If we needed to make any adjustments we could place shims underneath or on top of these pieces of cedar once we have them where we like them. We'll go ahead and use a couple pieces of the leftover tape and just tack those in place so that they don't shift. When we're sliding the window into place from the outside and once we have this second shim in place we're ready to prep the window. As you can see we're folding this nailing fin up. There's a couple different ways that a fin might ship to you. One it would already be in this 90 degree orientation. Two it could be integrated like this one but needed to be folded up or three. Three sometimes they'll ship separately depending on the size of the window or patio door shipped that way that you'd see it in a bead of sealing. Here we have it resting on a couple stacks of two by fours that way we can rotate and fold this flange out without having any worries. Now we're going to pick the window up and we'll do a temporary fit. The reason for this temporary fit is we want to make sure that we know first that the window is going to fit. We'll get it centered in the opening with the help of an interior carpenter and now we'll take and trace three sides of this opening around the fin and the reason for tracing this is this gives me a clear point of where I want my sealant to go after I set the window back down. That way I'm avoiding putting my hands in sealant, I'm avoid putting the window in and out in the wrong location. Now we'll set it down and we'll get our sealing. We're gonna apply a bead of silicone sealant to both sides in the top of this opening. We're not going to apply any to the bottom because we want to leave this sill open so that if water find its way in it has a pathway to the outside. The silicone that we're using we've checked we make sure that it is approved by the manufacturer of both our substrate and our window. It's not required by all window manufacturers but here we're just using it as a belt and suspenders approach. Now we're ready to place our window. Now we can tack it in two places at the top corners check it for level plumb and square. Now that we know the window is level plumb and square, it's time to finalize our fastening depending on manufacturer recommendations. It may be every hole or it may be every other you need to check with the manufacturer and the instructions they've provided. On this particular unit it's every opening. Now that we have our window securely fastened it's level plumb and square it's time to move on to final flashing.

The final flashing for this window involves a few more pieces of tape. We’ll leave the sill open still so that we have that available drainage. We'll have a piece of tape on each side and a couple across the head. Let me show you what that looks like because of our integrated flange. We want to make sure that our tape turns from the wall and in the flange onto the edge of the window protecting that joint between the flange and the window. I'll start by working in some small sections to make sure that I'm both in the location that I want on the WRB and on the window. Again I'm pushing it in place with my hand that way I can seat the tape where I want and I'm not relying on the placement of my roller to hold the tape where I want. Next where the tape transitions from being on the edge of the window to needing to lay flat I'll make a simple cut here and one at the top. I like to roll that piece of tape in, get it completely seated before I move on to the next piece of tape. That way I don't miss anything in my process. Same thing on the second side. We're ensuring that the transition from our WRB to the edge of our window is covered and is one continuous surface. Now that we have our sides flashed it's time to move on to our head again. This is a couple pieces of tape we have a vertical seam simulated on our mock-up. Here what we're gonna do is we'll peel this tape back. Fold it to the side we'll apply one run of tape the same as we did on the sides so that we're flashing from the WRB to the edge of the window past the flange joint and then we'll come back and we'll add a second one that's a little wider and a little higher and then we'll be able to fold this back over the top and everything will shingle as if it were a roof. We're going to take this first run pass whatever horizontal we have. That way we're completing our taping a little further out each time. The opposite of the verticals, we're gonna cut that a little bit so that we can lay it flat. We're gonna continue to work this flat and down onto the top of the window, bridging from the WRB, past the nailing fin and on to the edge of the window. Now this piece of tape I'll just seep with my hand, the next piece will roll both at the same time. So, we're gonna get a little wider and a little higher with each pass. We can seat that tape one more time and finalize its install with the roller. We're making sure we get on both sides of the window. Now we're ready to bring this head flashing tape back down. Just like the horizontal it gets rolled in place as well. Now that that vertical seam is rolled it's attached to our head flashing and down our sides, we're completely managed for water. If we wanted to we could add a head flashing and that head flashing would be taped horizontally with the vertical legs sitting over top of it just like we have here. We're not going to install a head flashing on this mock-up. Now let's go inside and talk about air sealing.

Now that our exterior is watertight we're inside and we're gonna deal with air and thermal. We're gonna do that using a spray foam application around the perimeter of the window. This method will actually apply no matter what your WRB is on the outside. Our goal here is not to completely fill the void we're just trying to fill the first inch or so from our side towards the outside. It leaves an open area on the outside of the window that if we ever have any moisture in that assembly it's able to migrate out. We're taking special care to be using the correct foam in this assembly. This is a formulation made for windows and doors which means it's not going to cause our jams to bow or bind in any way. Now that our foams installed we'll let it dry. Trim back any that needs to be cut away and then we have one more air ceiling detail. Now that we've given the foam a few moments to skin over we can apply a sealant over any shim that we have that will bridge from foam across the shim and back to the foam making one continuous air seal. [Music] Put those last beads is sealing in place the interior is detailed the exterior is detailed and we're confident that this is going to be a leak-free installation.