Slope The Pitch of a Roof 

Life saving video!!!. So well explained. Thank you 👏🏻👏🏻👏🏻

Brandon actually thanks a million man, I'm going into an oaks performance task and it's about this very thing. I haven't taken geometry in a while and this was an amazing refresher. I know this is two years old but it's still incredibly helpful. Thank you again for all you do. =)

so well explained and very clear. thank you very much

Excelente, muy bién explicado. Gracias.

You are my favorite Math teacher.

Thank you for your channel. I must advise that the three drawn examples to the right do not describe their associated names. A 12/12 pitch is easily identified with a peak having a square corner equilateral, 90° angle, where rise equals run, which would be the one you show second one down as a 8/12 pitch. As measured by my protractor, the uppermost diagram illustrates an acute angle of less than 90° at the peak; thereby having a rise greater than run, with a pitch of approximately 15/12. The bottom illustration is not a shallow 4/12 pitch. It is a familiar 7/12 pitch roof, which is slightly greater than the 6/12 minimum for snow loads in my region. I live in northern New England where a 12/12 pitch roof has been historically used on 75 percent of homes as a means of strengthening for heavy snow loads and for shedding snow, and for creating space for rooms, often combined with dormers, which would otherwise be unused attic. In contrast to your comments that are probably based on your region, steeper roof pitches up to 18/12 and greater are not at all uncommon in New England, and are frequently used in modern construction up here and in any snowy region. While modern trussed roof engineering has strengthened snow loads with lower pitches, accumulation of snow remains a concern, where steeper pitches of 8/12 and greater shed more efficiently and are less prone to "ice damming", the problem where ice melt at the eave migrates upward under shingles due to capillary action.

Really knowledgeable .. thanks

Thank you Sir. You actually end my day!

Thank you sir. Helped alot.

Excellent presentation! Good review of things learned long ago. Too long for me to remember all. Haha.

Great video thanks for sharing

Your video is awesome!!! Thank you

Your rafter is also called a Top Chord in the roof truss world Very well explained sir 👍🏽

A 15/12 or steeper pitch could be seen in Victorian and Second Empire houses, especially with garrets, turrets, and pinnacles, and generally in Gothic Revival -- oldies, but goodies, especially if one is into that sort of thing. PS: Go Tarheels. Cheers.

if my existing roof is a 6:12 pitch and I'm wanting to add a room into my house and my dimensions are 15x20, what would my roof pitch be

I had watched many videos and still not catching up but your finally feel I can do the math now. Thanks.

If you know the rise over run is there a way to calculate what the pitch of a roof is in degrees (45 degree angle, 50 degree angle, etc.) I need to do this for a recording studio project for acoustic treatment. Thanks very much. Philip

Amazing video! What is the software you are using to illustrate this? "NoteBook"? (I have a MacPC). Thank you very much!

Very helpful , Whats the name of the program you are using also

Thank you :)

Thank you so so much

On a lean two roof/building when rising the front wall to give the roof a fall back you are also increaseing the run, and the more the rise the longer the run??

Hi I use the terms rise run rake as in squared rise plus squared run equals the rake squared just seams easy to remember

So if I do a monopitch roof/shed/lean-to/slanted (so many names for it) on a 34 ft house like yours in the example with 3/8 pitch, I would have to build 12.75' wall on top of my existing wall at the high point to achieve that? Did I do that right?

Hi, I am from the UK and when we are setting out a roof we do it using the angle of the roof ie. 32deg, 35deg, 45deg. We don't use the 8/12 or 3/8 so using your way how could we do it. Thanks for any help.

A Steeple would use a 15/12 or an A frame. ?

Is that calculator program still available? Great instructional vid.

Im building a small pump house and my span is 30” and was going to do a 12/12 pitch. Would I multiply 1.25x12 to get my height of ledger board?

Don't get me wrong! I worked this out by watching ALL the youtube vids out there! And I realise that the "Old ways" are important! Using the "Step-off" method with a FRAMING SQUARE and a SPEED SQUARE from everything from a dog house to a single story home/garage etc! But my point is... If you're gonna take all that time to study all the different methods... Why not just SIMPLIFY! It shouldn't be all about the math and having to pay massive amounts of dosh for an architect or contractor... Anyone can do this with confidence with a little time spent experimenting with the drawings one can create with "Sketch-up"!

Why did you do 17x6,375 /by 2? Why did you use the hypotenuse?

Alternatively: Note that with 3/8, the hypotenuse to that is: Hyp = sqrt(3² + 8²)= sqrt(73) By ratio and proportion: Rafters/17 = sqrt(73)/8. Thus, Rafters = 18.15600796

Good video

Thanks 👍👍👍👍

Hi, does this work with meters? How do you work out it out please? I want to build a cabin 6m wide with a ridge at 1.5 m Thanks, Mark

Excuse my ignorance, but who decides the roof pitch to be 3/8 or how do you determine the roof pitch?

WOW!!!

pitch and slope are different terms meaning the same thing, angle of roof: 6:12 slope = 1/4 pitch.. 4:12 slope = 1/6th pitch, because the 'pitch' of a roof is always based on 'full pitch' 24/12!!

What if you don't have the 3/8 and your trying determine what the "3/8" is... For example what if it's 3/12 or 4/12... How do I calculate to determine my rise???

what program are you using on the mac?

very technical but!

Amazing educational video. Please post more videos like this one.

what is the name of the software you are using. Thanks for the tutorial

HI, what pointer do you use?

Slope is different from pitch in construction framing

I'm a bit confused, I always read it 7 inch to 12 inch not feet 😐 explain please (figured feet into total inches for easier math) Plus the 15/12 pitch would be a negative pitch as is an A frame.

where is the website you used to doodle with

You forgot the 1” 1/2 in the roof. The perhaps. 3/4 both side lol

I haven't done this kind of math for quite some time............... LoL!

The illustration of the 12:12 pitch is not accurate because a 12/12 ratio makes a 90-degree angle but the illustration depicts something more like 12/16...

If this is a maths class fair enough. If it's to find the length of a rafter carpenters don't take their Mac on site with them! So for those who aren't students and want an easier life, look in the rafter tables! That's why they're there!

Dear how to know 3/8

Why did you do square root at the end. ???. Always one peace of info left out.

I have 28 ft horizontal. What should be ratio?

What is 18.2 ft on a tape? 18'-2in

Why are we still doing these calculations in 2017? If computers are our future and we still use calculators to do the math anyway, why not download a FREE version of SKETCH-UP and build/draw your roof with the desired dimensions/slope... Place your RIDGE BOARD up there at the calculated height... and simply (using the LINE-TOOL), draw your rafter with the desired tail and birds-mouth... Make a "copy" of it and "move" it away from the building where you can then ACCURATELY measure all the dimensions required! Seems like a no brainer to me! Using "Sketch-Up", I was able to cut ALL my rafters! The most important task then was to make bloody sure the walls where squared up to spec! They where and there were no gaps in sight!

👍👍👍🇰🇼

I think your span measurement is wrong ...that's not your building dimention.

Dauwg gone it

I need 72 degree slope for a pyramid and the pyramid will be like 2 ft tall

I lost my savings for building a house without a ridgebeam.

Taking my B license test for the 6th time. I know right.

English please,,... 😉 Lol

Too many numbers, there must be a simpler way to do a simple pitched roof.

So easy when you study and look at things simply in math terms and not contractor terms who confuse people for no reason and try to get all technical. No offense. I work with many and go back to clients and have to explain like this video with drawings not engineering that also their terms and pages upon pages of useful but really overdone info generated by software.

I think you got confused.

Glad I'm a mechanic and not a carpenter, MATH SUCKS!!!.