How to Measure and Cut Rafters

I hope no one is using this as an educational video because this is wrong. The only reason it works for him is because he’s using a 12” pitch which is 45 degrees, and your angles will always make 90 degrees. Don’t believe me go try this yourself with any other pitch and you’ll see. There’s plenty of videos that show the correct way, this isn’t one.

So if the pitch was 7 12…… would you cut the long end of the bird mouth on that the 7 or at 45 still?

Awesome video very helpful answers a lot of questions

I almost forgot yall used house wrap as a vapor barrier a few years ago

taking out more than 1/3 of the timber for the birdsmouth unnecessarily weakings the rafter

We work with numbers and measurements...not theories.

Never seen how you determined the actual length of the rafter to make that measurement or did I miss something?

How many inches between each rafters? No one knows it!

Wow I'm just as confused as before I watched 😳

I like to eat a slice of pizza 🍕 while cutting it 👀

Hey Eric, excellent video.

Good video, makes cutting rafters not so intimidating

You make it look very easy!

To find out what your roof pitch is measure from the ground to the bottom of roof edge, then from ground to center of roof. Then divide the difference in height by half the length of the wall on that side. Then you have the rise by foot a.k.a roof pitch.

Is it always 45* for the 2nd cut of the birds mouth?

You explain it perfectly

Holy frick boys
Length of common rafter is
Length =√[ (height^2) + ( length^2) ]
To your birds mouth then
Overhang Length =√[(height^2) + ( length^2)]
Add that to your previous length and finish your markings and cut.

Also get in the habbit of plunge cutting. Its way more accurate just rest the toe of your circe saw on the lumber and blade where you want it over the line and ramp up your speed and cut into the lumber. Better cuts and you start with your blade already 1/4 way through your cut. It really saves time.

great vid amigo

This is exactly what the people want to see when searching this up every other video is bogus thanks

Lol why not attach a stick of timber to the outside of the top plate, measure up and mark your ‘height above plate’ on the stick and then run a string line from that height/mark to the top of your ridge? People won’t always be using rafters that big so if you teach them to make the birdsmouth the width of the top plate they’ll be cutting too much material out of the rafter and it’ll fail frame inspection. Better yet just learn the basic maths behind a gable roof when it comes to rafter lengths, angles and ridge heights. Basic trade school stuff lol.

Not to lie or anything but making all those lines aren't necessary it makes it difficult to understand the structure.

I really appreciate the video - it helped me a ton.

💥💥I appreciate your effort posting this but it’s not a very good tutorial on how to do every step of layout including the bird’s mouth since you’re not showing which way to orient and pivot the speed square.
This would have been much more accurate and informative if you picked a different pitch than a 12 on 12 and had to actually pivot the speed square for every cut.

Is that the 6-1/2” circular saw? Can’t find a 7-1/4” without it being a worm drive.

You guys are my favorite channel for construction. Thanks for sharing your knowledge!

Quick question. by every 12 it goes up 12 so the roof is a 45 pitch

Not very clear on how you got the length...didn't show!

I don't see any 12 12

Love your video. Having trouble cutting 2x8 rafters that have to match up to 2x4 trusses that are on now. I'm doind an addition and the process to match these is confusing and I am not getting it. Can you send me detailed instructions?

Best explanation on the internet for this. Really. Short and sweet and to the point.

I am adding a shed roof over my porch. How do o measure for this Chang in slope

Hi , as a carpenter of 40 years , I did a 5year apprentiship in which we are taught how to perform carpentry tasks . ? Do you not have any such trading in usa? You mention Pythagoras ? He knew 3, 000 years ago how to attain the length ? We are all in ore of his knowledge .

It's always nice to be able to refresh your memory if you're not a building professional like myself. Thanks!

what? huh? 😞

Nice job

Youre shit. Youre whole team id wreck

Oh you can't show us on a 2x6 like 99.9% of the roofs are made out of. Dann yankees

This is the best thing ever as long as your building specifically a 12/12 pitch roof. That “it’s just 45, mark mark mark”. Well…. Everything that ISNT a 12/12, isn’t 45. Love the videos !!! This one just left me cutting the ridge angle, placing it up there ( 12ft off the floor to a 10ft wall ), marking it from the wall, getting it down and cutting it like a cave man. Came out good. But I watched this like 13 times before I gave up and cut my 2x6x12 (7) times before throwing it away lol

Great vid dude. Awesome

Very helpful thank you!

firsr of all 12/ 12 is not a pitch . this roof is 1/2 pitch. Second a rafter book gives the exact length of the rafter You look thr span of the building say if it is 24' plus the sheeting 1/2'' plus 1/2'' so the span woud be 24' 1'' minus the thickness of the ridge say it is 6'' so the span is 23' 7'' look that measurment up and that would be the length of the rafter. from long point to short point at the top of the rafter. then draw a plumb line at the seat cut with a 6'' wide scrap and slide this down the plumb line until it touches the bottom of the rafter that would be the birds mouth the heel of the rafter is the part of the birds mouth that is the heigh above plate go into the living room and lay thiis into a corner on the floor the heel would be about 8or 9 '' high mark up 12' from that mark and over 12' draw that line then lay in the rafter and you could see the height off the ridge set it 3'' low and you have it.

Tank you for all the information

Isn’t it stronger to have a birdsmouth on both sides rather than a plum cut?

I love this video do you have one that shows the rafters above the main beam so I don't have to cut roof plywood for ridge vent

How much under is the main beam from the rafter point

Thank you

excellent video!

As someone who's watched probably over a dozen videos trying to get the entire picture of proper roof building, and isn't a dummy, lol, I appreciate this obviously experienced explanation.
I'm not a carpenter, I don't even really like working with wood. I'm an electrician/welder/operating engineer, but I like to learn and build my projects myself. Yeah, there's some fancy words used, and plenty of mistakes that get redone, as long as it takes me much longer.... hey I'm honest... but when it's finally right and done, I know every bit of it.

There's too many hack jobs out there thinking they're just slicker than grease, but they're work is sloppy and their ego is inflated, no way to build in my opinion, or teach.

My favorite time to build roofs and hang exterior wall panels... when it's 43°F and raining... it turns out... lol

Thanks!

Great explenation