Learn House Framing and Why it Fails

There's a lot of ways framing a house can go wrong. Some are obvious and some of the most important ones you can never see. So, I'm going to frame this house from the ground up and show you what happens when you get it wrong. We'll lay out our bottom plate and our top. When marking layout, you'll line up both plates. They can be marked flat or stood up. If you pull from the edge and make a mark on 8 ft, if you use this mark as your edge, an 8 ft sheet will land short. But, if you use this mark as your center, your 8 ft sheet will land on the center. So, keep in mind if you hook the outside of your structure, 8 ft will be the center of your stud, not either side. Now, we'll separate our plates, chalk a line 3 and 1/2 in back, line up our bottom plate on our mark, and pin it down at this angle. When these nails get shot in, and this gets rolled over, cuz the bottom of the nail is still in this direction, when this wall gets stood up, it gets locked in from kicking out. If we don't, the bottom can slide out. Lay out your studs crown facing up. Nailing the bottom plate makes it easier when you push in the studs when you go to nail. Flush up the face of the stud and don't nail your hand. You have your roof and rafter, your sheathing, your double top plate, your bottom plate, and your studs. Double top plates distribute loads and help support your roof. It also allows for seams and plates to move along the top. If we don't install these plates, when the rafter's point load is in the middle of a stud, the single top plate can be weak. While a double plate is strong, but even with the 16-on-center being closer, a single plate is very weak. This is why 24-on-center can be weaker than 16-on-center. For a California corner, you'll attach an L. This three-stud corner saves on material, but doesn't allow space for insulation. Or four-stud corner allows more thermal bridging inside and outside of house and gives no room for insulation. If we change for this three-stud corner, this gives space to stuff insulation behind your stud. And these will butt up in the corner. All you do is frame it like normal, but this 2 by 4 will sit on the deck. For wall openings, double-check your required rough opening size and you'll need to frame in jack studs and your required header size. Shorter openings can get headers that have less depth. Once this opening gets so wide, your header will need to be taller. Depending on snow load and roof span, you might be able to use a 2 by 6, but if your area gets a lot of snow and your roof span is longer, the sizing might be a 2 by 10, 2 by 12, an LVL, or even bigger. The spacing's usually 12 to 16 on center and you can either stack your nails or offset them. You'll double up with a jack and a king stud for doors and windows. If our rough opening is 82 to the bottom of the header, all you need to do is take your jack, take the rough opening height, and subtract the bottom plate. So, we'll go 82 and 1/2 and then subtract your inch and a half, and this is where we'll mark these to cut our jack. Install your jacks and your header. When you nail your jack studs, you want to be sure that they're flush and then you can join these together. If you only nail a header up without the jacks, the nails are all that support the header. But if you install jacks, give the header support. When you put in this header and go to nail it, you want to be sure it's pulled fully tight, so you don't end up with some crazy gap. The header can be installed at any height. You can go up to the top plate or it can sit down at any height. If you don't install cripples, weight on your top plate can cause this to flex. The cripples transfer weight down, around, and into the footings. This makes the top plate strong. If we remove our cripples, roof loads can damage your top plate. If you install your rafters over the top of your studs, it gives it a point load. The point load from the rafter runs all the way down the stud into the bottom plate and down into the foundation. This can be important with places with high snow loads or if you have a really long rafter that puts a lot of weight in one place. You can install cripples on your header first, but if the cripple's short, it can be hard to get your gun in here to nail. But, if you attach it to your header first, it'll be easier to nail. Sheathing is what locks your structure in place. And nails resist shear forces. When you don't properly fasten the sheathing, the structure can still move. Until the sheathing gets fully fastened on the studs, typically you'll have five in the field, but just with one sheet attached, this is much stiffer. Before we attach sheathing, we need to square up the wall. Pull a measurement from corner to corner and be sure the measurements are the same. If you need to make adjustments, you can push or pull this framing and this helps square the walls. Essentially, all we do is move this wall in either direction until it's square. As these points get closer, the other points get further. So, when we put on our sheathing, our wall isn't racked either way. If we line up this corner and line up our long edge, we can use the edge of the sheet to square up our walls. Depending on how much your sheathing needs to overlap to go down and cover your rim joist. So, when this wall gets stood up, this sheathing will go all the way down and can get nailed into the sill plate. Subtract that distance and then we'll make a measurement up. And now we can use that mark to snap a line. We can line up the sheet on that mark. And you're going to want to install the rough side out. And remember to stagger your seams two bays. And nail down your sheet. If you don't sheet your walls before you stand them, your walls can easily move. Regardless of method, there's always an easier way. If you struggle lifting sheets, you can use a deadman. And this lets you adjust up and down, and then you can tackle one side and lift it up to your line. You want to be sure you stay on center. If this stud is bowed and you nail it, as you work your sheets up, now that this is bowed, your next sheet might not line up. So, when you continue your sheathing, this sheet will miss the stud. But if it gets done right, your next sheet should line up just right. Anytime you nail, you want to be sure you're not going too deep. If you go too deep, the sheathing will barely hold. When you're nailing sheathing, you want to be sure that you're using ring shank nails. And you also want to be sure you're using a shorter nail. These are usually 2 and 3/8 and have rings on it to resist pullout. Here's a smooth shank. Here's a ring shank. For the smooth shank, they pull easily out. For the ring shank, a little bit harder. Overlap your sheathing and snap a line. And this is where you'll cut. And just take this sheet down to the other side and mark out your openings. Sheathing on the ground makes walls heavy. But sheathing after can be a lot [clears throat] more work. Before we stand up walls, to help you get started, you can pry the plate up and slide under a 2x4. And this gives you space to get under the plate. We'll screw in a side brace. Depending if you set your brace higher or lower, will determine how much kickout it has when you lift the wall. So, now when you lift the wall, now we can adjust our brace, plumb our wall. If we pull the rim joist and install a wall parallel with the joist, when you nail the bottom plate, nails need to go into the bottom plate and down into the rim joist. On the side where the joists run perpendicular and there's also the rim joist, and nails also need to go into the joist. So, one nail in the rim and another one in the joist. Now, we'll just bump over our plate until we're on our line. Now, install your double top plate. The top plate seams don't have to land on a stud, but when you can, it's best to land them on a stud. Installing top plates is easier when the wall's on the ground, but doing it after sometimes is easier and leaves room for adjustment. Wall intersections need to be properly tied together. This plate will overlap the other and this plate will lock these together. And the second double will just butt right up. If we don't fasten these corners, these walls can fail. You can cut double top plates at the same angle as your roof pitch and calculate your take. You'll just take your stud spacing, times it by your pitch, and then divide it by 12, and this will give you your take. If you hit inch twice, it gives you 9 and 5/16. All this is is how much more length each stud has from the outside stud. For the seven pitch, it was 9 and 5/16, and that's how much each one of these studs gains until you get to the peak. So, if these are all 9 and 5/16, this is one, this is two. Now, over here, it would be three. And this will go until you make it to your peak. Trust your math and nail it in. If you do your math right, there's no need to check this. Up top, you could do measurements, but in this case, they should just line up. Nail your one end first and then nail your peak. Now, when you scoot all these over, if you measure your spacing, this spacing will be 16 on center. This has continuous studs that run from the bottom plate all the way to the top of the rake and resists lateral forces. Sometimes this is called balloon framed, but it's technically a tall wall framed or continuous stud. It goes from the top plate all the way down. This corner requires proper fastening so it doesn't spread apart because the top plates don't overlap. For a platform framed rake wall, it has overlap top plates and this is what keeps the walls from separating. If you platform frame and install a double top plate, it's easier to install your rake, but doesn't handle lateral forces as well. But platform framing a rake wall can be more forgiving. Roof pitch adds to the height of your structure and determine how low your rafters hang down depending on the size of your overhang. Steeper pitches allow water to flow better, but are harder to walk on, more expensive to have work done. Lower pitch roofs are easier to work on, but can be more of an issue for water and ice dams. For rafters, you'll measure your structure from end to end, then we'll cut that number in half, then subtract half your ridge, typically 3/4. 12 ft is 144 in / 2 gives us 72 in and then we'll subtract 3/4 of an inch and that gives us 71 and 1/4. This number will be our run and we'll do a 7-in pitch and our diagonal will be 82 and 1/2. We'll mark out our pitch, the bottom numbers are common, put down your square, turn up until the top lines up with number seven, make your mark, pull the measurement from our long end, mark 82 and 1/2, draw out another seven pitch. Now rotate your square and use this line to determine your seat cut and you can leave this long to cut your rafter tail and install your rafters. When nailing your ridge, if you hold the rafter a little high and top nail, it's much easier to knock this down and then finish your three nails. When installing rafters, if your walls bow out, nothing will hold your ridgeboard. If you install a rafter tie, if the walls can't bow out, this is what keeps your ridge from separating. Bottom cords for rafter ties and trusses are in tension, so they're getting pulled apart. If we remove the rafter tie, or if the rafter tie doesn't have enough fastening, it's typically a lot more than you think. If plates let go, nails let go, or this gets cut, it lets the walls bow out. If we install a ridge beam, this keeps your ridge from pushing down and bowing out your walls. So, if you end up wanting a vaulted ceiling, so in this case you have loads on your exterior wall and your center beam, if your rafters aren't connected well, these can still bow out. So, in this case nailing alone isn't enough to keep this from spreading apart, and just a collar tie isn't enough, either. It's common to strap over the top of the ridge to avoid the separation. Keep in mind for your ridge beam, it's not going to just be a 2 by 4, it'll most likely be an LVL unless it's a really short span. And then install your subfascia. For your fascia, instead of landing a seam in the middle of your rafter, just install a block in between the rafters and land your seam there. Consistent measurement on your plates and your ridge height are two of the most important measurements you'll get. If you follow these measurements and you don't make deviations, by the time you get to the top of your building, everything will line up and it goes way easier. Even if your building is out of plumb while you're building it, as long as these measurements are the same, when you plumb your walls, everything should still line up. One mistake is all it takes to throw your building off, and then you'll find yourself trying to compensate, and when you compensate is when you end up making more mistakes, and then it never lines up. As you build, you need to install bracing. Lateral bracing keeps the structure from racking and potentially falling. We'll screw down a brace and use a wedge to prop under this brace. The more that we push, the more it pulls this wall in that direction. We'll cut a small piece to push off this exterior wall. As this gets pushed down, it pushes our structure this way and install a lateral brace. Another option is attach your brace on the bottom, put it in the corner, and then just push down and this can straighten out your structure also. Don't forget that houses do fall down. One brace is really great here, but you'll need braces in different areas and even on the roof before you install sheathing. Hurricane ties or other fasteners attach your rafters or trusses to your top plate. This connection resists uplift and creates a connection all the way to the foundation. If one of these doesn't get installed and you get uplift, your roof could blow off and that's not good. Install your roof decking. It's best to have this overhang 3/4 to an inch over the eaves. This gives room for drip edge and other finish materials. It's often thought that studs is what keeps a structure from falling over, but studs mainly handle downward forces. Even if you add sheathing, without nails isn't doing much. So, the shear force of thousands of nails is actually what holds your structure together. So, if you don't make the proper connections, when your connections fail, your structure will fail. Thanks for watching.