Why patio roofs fail - and how to build them right!

This is how your patio roof fails. And what keeps it standing? Before you install your ledger, we need to be sure this gets properly attached. You may be able to attach your ledger directly to the studs with nails. And this will typically require a 16d nails, not just nails from your gun. But this method can have less pullout strength and isn't allowed everywhere. If we use structural screws, we can leave on the sheathing and attach our ledger directly to the stud. And this makes the ledger resistant withdrawal. And this can handle much more shear. When ledgers get directly attached to studs, you need to be sure the fasteners go directly in the middle of the stud. Also, if the screw gets installed too high, then this short section right here is all that's actually holding the ledger up. See how this just chipped off? If we don't properly install the ledger, if we just randomly install nails, just because we used more nails does not make this any stronger. And these nails will only hold into the sheathing. To remove your siding, we'll use a removal tool. We'll hook this up into the seam, pull down our seam, and then push this back up, slide down our siding, pull your nails in this seam also, and remove your siding. Get your level mark, mark out your studs, and attach your ledger. And these fasteners get installed on all your studs. Then we'll measure out from our structure. In this case, I'm doing 7 ft. Now I'm going to mark the ground in two spots. The diameter of your pier needs to be a certain size, and these footings need to be dug below your frost line. We'll drill out our footing. This style counts on drilling down into the concrete and holding from uplift. For this post space, we'll install a wedge anchor. The wedge style expands on the bottom, and this is what keeps it from pulling out. So now when the post gets attached, and this beam gets installed, your beam and your post handles all your downward loads and uplift forces. When installing connectors and hangers, you need to be sure you're using the proper nails or screws. If you just use a random screw or a deck screw that is not tested, span chart is how you'll determine your lumber size. If these rafters are closer, you can use smaller dimensional lumber, but as the rafter spacing gets further, these rafters cannot handle the same amount of load if there was more rafters. If you have a short span from your structure, you can use smaller dimensional lumber. Because there's a shorter span, there's less weight on this lumber. If your rafters span further, your lumber will need to be taller. But regardless of how many rafters you have, it does not change the amount of weight that this beam will hold. The square footage of your roof and your loads is actually what determines beam size and the distance between posts. So less posts need a taller beam and more posts, you can have a smaller beam. If we over span these rafters, these rafters can snap. To figure out where your post is going to land on a footing, put your level down from the outside of your ledger, tack up a straight 2x4, and this will line up with your outside edge. Now I'll just measure to the outside of my beam, then I'll make a mark, and now we'll square this corner up with a 3-4-5. So I'll just hook the outside and make a mark at three. I'll mark this side at four. Now I'll measure between both my marks and make sure that I'm on the same side of the tape measure, and then I'll just move this here until I line it up on five. Now this 7-ft mark is where the outside of the beam lands. I can use this measurement here to plumb down here and make a mark and then measure over that 10 and 1/2. Remember that the longer your rafters are, the further your beam is away from your structure, the lower and lower this will get. And this can be a big clearance issue. You either can calculate from the top of your ledger or the top of your beam. I know it's 7-ft from the outside of the beam, so this is how I'll make my calculation for my rafters. We'll mark down from the top of our ledger and we'll mark the top of our rafter, which is 20 and 5/8, and then we'll subtract the height above plate, which is 4 and 3/4, and that gives us the top of our beam. The height above plate is just from the bottom of the seat cut to the top of the rafter. Then we'll make a level mark down from our outside rafter, and then we'll level and install a temporary brace. You can measure up from your post base to determine beam height, or you can set a laser on the structure and use that. The top of beam height that we determined is if you have no seat cut on your rafter, but if you add a seat cut, this beam will actually have to be raised from that distance, so the rafter doesn't actually change at all. The beam height is actually what needs to change. All you need to do is take your plumb cut and add this number to your post size. Just be sure when you cut your post, you subtract for the height of your beam. For our post, we'll just mark it out to the height of our beam. Now we're going to subtract our beam height, which is 7 and a quarter. We'll measure down on the post and make that mark, and then we'll add our rafter's plumb cut. This is the top of the beam. The beam sits all the way down to this mark, but we'll add for our seat cut. This mark can change depending on the height of your plumb cut. Say this plumb cut was higher at like an inch and a half, you would just add that to this post, and that would make up for the difference. If your post isn't really tall, you can get away with a 4x4. In most cases, especially if you have a big overhang, you're going to want to use a 6x6. Now we'll laminate our beam. This beam length will be the same as your structure. These beams will often get laminated 12 or 16 in on center. Install your connector. Need to be sure you're using the proper fasteners. This is a 10D galvanized nail because this is pressure treated, you need to use galvanized. You just want to be sure you're not using the short hanger nails. While it might seem like this would work, you actually need to use these for this connector. These connectors might look the same, but this one fits tightly on a double 2x, as where this one is made for 4x4 posts. You use this bracket and you attach it, you end up having to smash this steel, and this is not the right connector. So even though they look similar, be sure you buy the right ones. Now I'll set my post and then I'll attach my post. And you could level and brace this post right now or you can set the beam so you can make some adjustment. If you have to lift a really big beam or you're worried about this moving, it's a good idea to run stakes. Before you go and nail it in, make sure your post is plumb. And now your post will stay plumb and set your beam. If we don't install braces, your beam could fall. Now this beam and your ledger will hold all the weight of your rafters. And your rafters connection to the ledger is also another critical connection. If your rafters aren't connected well, they can fail. If we don't properly fasten our ledger, then it can fail. It's also very important your rafters don't pull away from your structure. Your rafters could pull away or your ledger could pull out. Now we make sure the outside lines up on 7 ft. Tack our brace. Now we'll use the 3-4-5 and square up our structure and install your rafter. Our distance from the face of the ledger to the outside of the beam is 82 and 1/2 in and that's our run. And then we have a 3-in pitch. And if we hit diagonal, this is the distance from the top of the ledger to the top of the rafter above where it sits on the beam. If we hit rise, this is the distance from the top of the ledger down to the top of the beam and this does not include a seat cut. We'll mark out the three pitch on the top of our rafter. We'll hook this and measure back 85 and 1/16. We'll mark the top, draw out our pitch. Now we'll measure out our seat cut and we'll make our seat cut 3 and 1/2 in. So our plumb cut was 15/16 and our seat cut was 3 and 1/2. Could have also measured out and made a cut for our rafter tails on this end, but we'll just save it till the end. If you did your rafters right and they're all cut the same, as you go down, your seat cut should sit completely against this beam. But if the gap on your rafter starts getting bigger, you're at a quarter, a half, an inch, that means you made a mistake. You either cut your rafter wrong, your beam is set too high or too low, or your ledger might be set in the wrong position. You also need to transfer your spacing from the ledger to the beam. Measuring after the fact is more forgiving. Doing this on the ground is easier overall. And tack in your rafter. And install your hanger. This style joist hanger is made for rafters. This is just handling downward forces and pushing away the beam. And this situation is different than when you have a rafter sit on top of your double top plate. This counts on the downward forces being handled by the double top plate. Now we'll measure out our beam spacing and nail down our seat cut. This connection handles downward force. If we just install a rafter and poorly nail, It might not be one load that makes this fail, but consistent downward loads and pulling away from the structure can cause this to fail. This rafter will cap the end of our ledger. And now we can nail this on the end. Then I'll hook the chalk line and pull it down. Mark your rafter tails, and we'll chalk a line so we can cut all these rafter tails. I'll just set this up and put a rafter gauge on my square. Make sure this is level and then mark it. And we'll mark the rest of our tails. Depending on what handed saw you use and what hand you cut on depends if you want to mark it on this side or turn and mark it on this side. As you see here, the saw won't fit on this side, so these marks are pointless. And as you see here, you don't want to miss any. Attach your fascia. When you install fascia, you want to be sure it's in plane with your rafters. So you just lift your fascia up until it hits this mark, and then you can nail it in. If you have some twist in your lumber, you can make a wrench like this. All this is is just plywood screwed together, and this is about an inch and 3/4. You just take this and twist, and this can help straighten this out before you attach a fascia. Now we'll install a hurricane tie or a rafter screw up into the rafter to hold for uplift. If If don't have a gun, it could take a long time to fill all these holes. This has a marker for your plate line. If you install this and it's too low, it'll get in the way of your finished material. But, this needs to go up all the way to the plate line. Using the proper screws for this application can be a lot quicker. Just be sure you install them the right way and it's the proper screw for the job. And install your roof deck. Match up your overhangs and nail down your deck. As we nail, the sheer forces of the nail will start to stiffen your structure. On the seams of your decking, you install H clips. An H clip just goes onto your decking and then the other sheet will slide right on. This just helps with spacing and so these don't flex as much. If you have a small cut, you can put a stair gauge on the front of your saw and install the rough side up. If you're using OSB, you need to make sure the rough side is up. The opposite side is super slick and on steep pitches, you will slip. If you overdrive nails, your sheathing can fail. So, be sure that your nails are just right. Typically, you'll have two on the ends and three in the field. And now the sheathing makes the structure strong. So, if there's no sheathing, this can simply move. While adding a 45° brace can help with this racking, it only makes this so strong. This method is common in pergolas because there's no sheathing on top. Diagonal braces on the roof would be stronger than this. But, even if the structure sheeted, without the proper connection, this can still rack. So, it's important your structure is properly engineered. Every project is different and things change depending on your local codes. Now, I'll build out my beam. So, the beam is wider than the post. So, when the aluminum comes up, it looks good. When installing your F channel for your soffit, you'll want to level over from the bottom of your fascia and then make a mark at the height and install your F channel. Regardless if you use staples or nails, you want to be sure that your F channel has room to move. So, you don't want to overdrive either of these. Install your dripper apron. Install our ice and water. Cuz this is not a conditioned space, you don't have to use ice and water. But in some areas, you might have to use this on the whole roof. And install cap nails. This has two sides, and now you can just peel the bottom side. If this isn't adhered and nailed down, you can easily slip on this material, especially on steep pitch roofs, so be careful. And install your felt. Cut back the house wrap. Then we'll cut along the deck all the way down to the other end. We'll fold up the house wrap and tuck our ice and I slit the flashing so it can go over the top of the ice and water. And now this can fold over the other flashing and also cover this corner. And now the last piece of felt will run over this top. It's often thought that the ice and water sits on top of the paper, but it does not. It's made to protect the deck when we install an apron flashing. So now water that gets behind the siding runs down this apron and onto the top of the shingles. Your shingles will line up on your starter strip, but you have to be sure they're offset. If water gets between these shingles, they'll be on the roof deck or on your felt. When you install your starter strip, this sits under the seam of the shingles, so water that ends up making it into the seam will hit the starter strip and then run off the edge of the roof. So we'll line up our shingle. And now you'll offset your shingles. You want to be sure that you don't have a nail where this seam is going to land, so you'll nail it at the end, but leave this space open so when this sits down, there's no nail at the seam. And you can add an extra nail for wind, and I'll continue this step pattern all the way up the roof. And now you can just take a shingle, lay it down, and use this to cut your edge. Now we'll staple up our soffit. The soffit just gets tucked up in your F channel, and be sure you're using galvanized staples, and staple it in the grooves. If you staple in the center, it'll bow this in and make it look bad. You want to be sure this groove is fully in because if it's not, this will hang down and that this edge is not past your fascia. Now we'll install a cap post and a bird box. This can be done in a few pieces. You just want to be sure that you have places to fasten this on the bottom edges. We'll install this fascia after the soffit. We'll start by getting a plumb cut at the top so it fits at the top. Now we'll mark our beam and fold it in. Mark and cut our fascia. Now we'll install this front fascia. If we face nail an overdrive nail, this can dent and oil can your fascia. We'll install a J channel on the inside to accept our soffit and now we'll install our interior soffit. This could be vinyl, a tongue and groove wood, aluminum soffit, or other materials. We just need to be sure this is short of the edge so the fascia can come down and cover this edge. Pressure-treated can corrode aluminum, so we'll wrap our post. Now we'll do a two-piece post. We'll bend over these tabs so it can cover better on the beam. You can bend this to lock into each other, but it's a lot more work and you could also wrap the post and the beam with PVC wood or other materials and wrap your post. And now we'll notch out our beam for our post. We're going to install this J channel and install our siding. Now water that goes down the vinyl siding will hit the J channel and run down the house and water that gets behind the siding will run down and come out on the flashing. So before your new patio looks like this, be sure that you build it right. Thanks for watching.