Calculate and Cut Rafters with Birdsmouth Joints

>> [music] >> Nick, you ready to get right after it? I'm going to get right after it. Making a list of things to pick up for tomorrow. So far, a box of framing nails. All right, well, right rafter that. Get it? It's like after. Yeah. That's a good one. All right. Roof time. We're going to start out here by figuring out our rafters. And this isn't super complicated, but it's a little bit different in the way that you need to figure out your run, your rise, all of that stuff. And I'll show you why. So, with a normal A-frame roof, you're going to be measuring outside to outside because that's where your bird's [music] mouth is going to land. But, imagine this here. We're going to have bird's mouth on the outside. It's going to be going up. And then on the inside is going to be the bird's [music] mouth over here. So, really our run is not outside of post to outside of post. It's outside of post to inside of beam. That's another thing to kind of be aware of. It's not a huge difference, but we have 5 and 1/2 inch post and we have a 5 and 1/4 inch beam. So, we measure from outside of post to inside of post, then add a quarter inch, that's going to be our our run. >> [snorts] >> Now, we can put into our construction calculator that run, our rise, which we already know from setting our beams is 47 and a quarter. And that's going to give us our diagonal measurement. Our diagonal measurement here is 100 and [snorts] 89 and 3/4. So, that's really all the information that I need to start marking out this rafter. We'll test fit it and maybe make some adjustments. I don't know. We got a couple interesting things happening with this, so we'll see.