Rafters are essential components in transferring the weight of a roof to the walls or other load-bearing elements of a structure. They distribute the load evenly, ensuring stability and can be used on hipped rooves and those with gable ends. Valley rafters are placed where two roof planes intersect, running diagonally from the walls to the ridge and supporting rafters that run perpendicular to the ridge.
Hhip and valley roof components are used on hipped rooves and those with gable ends. They serve to support rafters and have two important structural aspects: sizing the member and providing support at the ends. In plan view, hip and valley framing are crucial for constructing complex roofs.
Framing complex roofs is challenging, but it can be done using accurate measurements and construction calculators. A common rafter runs perpendicular (90° when looking straight down on the roof) and frams the top of the wall plate to the roof ridge, forming the hypotenuse or diagonal of the roof. Valley rafters should have full bearing on the diagonal portion of the 90 degree exterior wall top plates.
A supporting valley is needed when there are two intersecting roofs with ridges at different heights and no place to post the lower intersecting ridge. It shouldn’t be necessary to cut valley rafters into the existing roof as long as the existing roof supports the weight of the new one. A beam from the exterior wall to the load-carrying beam in the basement can also cross the hallway.
In conclusion, rafters play a crucial role in transferring the weight of a roof to the walls or other load-bearing elements of a structure.
📹 Valley Rafter
Http://www.AsktheBuilder.com founder Tim Carter shows a valley rafter in a common-framed roof. Discover more information on …
📹 Making and fitting valley rafters The Big Build 30
I am making and fitting valley rafters here at the big build, this is a job I really like and its really easy with a metric framing square.
This gives me a better explanation but what am I missing here? I am on my way to train to be a draftsman at one of their tafe campuses; and the description of a valley rafter I was given in their book according to the Australian standard, off course, said to me probably everything you shared with everyone out there. The description in their book said to me that the valley rafter is located at an internal angle change of roof direction and in many ways is similar to the hip rafter. However, there is the added complexity of supporting the upper end of a valley rafter which, in many instances, may be located partway up the rafter length of the adjacent roof plane and often removed from a structure that can adequately transfer its load to a wall. Well, what do they mean when they say, “often removed from a structure that can adequately transfer it’s load to a wall. I am now left puzzled that pieces of timber do not just pick themselves up and walk away. It sounds like they’re speaking in technical terms, I understand you everything you show me but maybe you can give a description of what they mean from what I shared here.
Your original comments were in violation of my Comment Policy. It’s clearly stated in the About section of my website. Sorry about that. Your best option is to focus the energy you put into comments into articles at your website. I went to your website and there’s not one building article there. Because of that, virtually no one here will feel any of your comments are of value.
Hi Tim, i am curious what the name of the cut is at the top of the rafter, in a situation where there is only one truss/rafter and not double like in your article. there is a bevel cut on both sides to create a point in the middle, if done properly. I thought it was called a birds mouth, but apparently that is a notch for a truss to sit on a wall plate.
I hate to say this, but you don’t have a clue. It’s obvious from your comment that you’ve never framed a roof with hips or valleys, or if you did and did it the way you mention, then you did it wrong. I’ll give you a clue. Think of the top surfaces of the framing members as just LINES in a three dimensional drawing. Don’t think of the rafters as solid objects. Therein is the answer. Think where the LINES intersect. Next time THINK before you type characters on a keyboard.
TheShamus19, I wanted to make sure everyone realized that you’ve switched gears here. This article is about a valley rafter and your comment is talking about a ridge board. You’re 150% correct that ridges are in compression and you really don’t need a ridge board so long as the two rafters touch one another. Valleys, however, are in tension and you absolutely need a center framing member. Valley rafters are beams and have lots of weight on them. We probably should have not been so harsh to Street.
Simple on the double valley rafter. Remember the valley rafter is a beam. The valley jack rafters transfer their weight to both the ridge and the valley as they *bear* on the valley, not the top plate of a wall. Hip ridge rafter are NOT beams as they are in compression. Valley rafters get loaded with vast amounts of weight, especially here in snow country.
I’m also a bit baffled as to why you’d have 2 valleys together on that. Firstly, we aren’t allowed by code to use a 2×8 hip/valley/ridge on 2×6 rafters, unless it’s 6/12 or under. It would usually be cut out of a single LVL or a single 2×10 on a span that short. Thanks for posting these articles though, as someone who has done this for a living most of my life, I am fascinated by seeing how others go about their stick building.
@starlite528 That’s a fantastic question. I’ll bet you can figure it out by yourself if I give you this clue. If you were to put a straightedge on the TOP of the rafters and sild it down, where do you anticipate the tip of the straightedge would contact the valley rafters. :->>>>> Isn’t that interesting? You have to think in three dimensions.
I would normally use treated timber (Tanilised) for cut roofing. Your cuts are very neat and you know what you are doing. I also like to leave my common rafters about an inch shy of the top of the ridge board. we use graded timber here in the UK so it reduces knot size and any bad grain etc. You have used oversized timbers which is good structurally. Thanks for vid.
Lawson, you never asked me! First, the name is just valley jack rafters. I’m assuming your roof is a square or a rectangle, not some weird reverse gazebo or some other very odd valley. If the valley is indeed a 45 degree angle, all you do is set your circular saw table at 45-degrees. You mark on the face of the rafter the plumb cut line for the regular roof pitch. If the roof is 9/12, you make a 9/12 plumb line. Cut along that line with the tilted saw blade. Ta Da! VICTORY! It’s that easy.
those cuts are nice . just looking at the shortest valley jack tells a lot of the quality of work, When that one is off means something is slightly off, agree with ask the builder the ridge is a small concern but with valleys or supporting valleys their may be a. concern, when commons sags with a roof load that’s where the focus is, on both sides .the trouble dos nt start at the top .
Yes, you were being harsh. That’s why you removed your original comment. Realize that not everyone does things the same way and not everyone has the same skill level. I do agree with you that those that aren’t aware of at least one right way to do something should refrain from criticizing others. How is business down in NZ right now?
does a valley rafter need to run all the way down to either a bearing or exterior wall? am I able to chop it, obviously where its no longer hold up anything, and then run a 90 degree beam plumb down to a supporting wall? – am I making sense? (I need to allocate a space but a valley rafter is running right through it)
This is from the New Hampshire gov’t website which links to the IBC. R802.3 Framing details. Rafters shall be framed to ridge board or to each other with a gusset plate as a tie. Ridge board shall be at least 1-inch (25 mm) nominal thickness and not less in depth than the cut end of the rafter. My concern is, what does a potential home buyer do? If the builder doesn’t know the code, and the inspectors don’t enforce the code, where does this leave the buyer?
Reading the comments some of which are more like complaints I have to laugh. This roof is not that large. Having framed a 19,000 square foot hip roof with 2 valleys on a U shaped building with the main section being much larger, taller, and looking at the 1905 and 1912 houses we live in here which only came with 2×4 rafters I’d say it it is just fine.
So, how do you derive the angles and lengths of each valley rafter? Are the valley rafters on 16″ or 24″ centers so that the plywood roof sheeting will break on the center of the rafters properly? Do you think that you could show how to calculate the length and angle of a simpler “common” rafter (including the “birdsmouth” cut)?
Hi I need help. I plan to build a vaulted ceiling roof over my deck and my plan is to build half truss with 22”x 17′ long ridge beam with is very heavy duty the span is only 22′ long and the 16′ length but the safety department won’t provide me the permit for the half that I plan to build my own. It is very simple for me and very strong to my roof. will you answer my question? If I go ahead and build the roof over my deck I want without a permit, Are they gonna tear my beautiful roof down? or a fine, how much is the fine. I feel I have lost my freedom from using my professional skill that I am good at the structure, maybe better that the structural engineering. Thanks, Please let me know.
Right every time if one knows how to read hip&valley cuts on a framing square…that has those tables of reference embeded on it. Or short cuts on how to swing arch a steel tape to determine the long to short of the overall length of the cut. Its quite simple once one understands the right way its achieved. And each there after is short or growing longer by inches as set in the tables on the square. Or one can get a Mi-Tec software to do a take off on every cut board to its entirely correct way of each saw cut being fully correct in the build of the roof components it will dictate. FYI.
Yes!!! Thank you. I’m a Journeyman Carpenter/Craftsman with roughly 30 years experience in construction. I’ve taken my craft seriously, and it’s refreshing to see another Craftsman that does his job well… really well. I rarely even make it all the way through a article, and if I do, I stink up the comment section. Well done man.
“Get your cuts right way ‘round.” A pleasure to watch you work – and the perfection of your geometry. I suspect, though, that you are doing self-checking (like, “measure twice”, and “is this on the right side?”) that you omit to keep the article a reasonable length. At least that’s what I find myself doing on much simpler structuring. And (fortunately) finding errors before they become “discard and start over.”
Impressive as usual. Never could do that. Not able to work them out geometrically only by measurement. Then mostly worked on centuries old buildings far from true anyway. My hack way uses a string line to get the line and level. Offcut templates for top middle bottom placed to the line square ends pinned in place. Measure the two gaps then lay out pieces on Valley rafter with those spacings and you have a segmented overall pattern that should fit. Also works for hips and multiple birds mouths such as when the engineer sticks the big steel just down from the Ridge. I never had your skill level or confidence my cuts would be right so cutting them first on Offcuts a must for me. Not pretty but you have to work with what you have. But at least I then didn’t waste timber getting cuts wrong.
– 3 science A-Levels (including Physics, which is basically applied Maths), – A science degree -Post graduate training in health economics and mathematical models – 15 years spend using said skills in technical / scientific jobs – Time spent on building sites working with family who are in trades – Carpentry / woodwork is my main hobby …And keeping up (or rather trying to keep up) with what Robin knows makes my brain HURT!!
Robin, this lesson in fitting valley rafters, as well as all of your articles, clearly shows the experience that has gone beyond the academics of the craft. To quote Albert Einstein, “The only source of Knowledge is experience.” It shows in how you approach planning and execution, the ease in just picking up and using tools, your ability to describe what is going on, and being able to reinforce how you got to where you are in the project by starting and remaining square, plumb and true throughout the project. Thank you.
Today showed me.. (when working with some other “chippies”) who’s is a “carpenter” and who isn’t…. I’m a modest man with 3kids and a mortgage…… I was trained in Ireland 20 years ago and I do my best to be modest; but fuck me this is easy but in comparison to what I’m working with …… I’m fucking brilliant 😂😂😂😂. KINDLY KNOW YOUR JOB! Thank you Rob for knowing your Trade Sir.
Next time do not put any rafters next to the valley.l seat. Nailer one piece of 2×4 on the top of your left roofing rafter to end to the valley and later put the main valley rafter and with adjust to the 2×4 ( under 2×4 ) THE 2X4 will show you the correct point that you need to put your valley rafter. Advice = Master Carpenter in USA 🇺🇸
The Hip and Valley are exactly the same length…. If the span of the common rafter is say 20′ and you have a rafter book you would look up this span minus the thickness of the ridge san 1 1/2 so you would look up 19′ 10 1/2” under common rafters That would be the exact length of the common no shortening If you look up 19′ 10 1/2” under hip or valley that would give you the exact length of the Valley no shortening as far as the seat of the valley if there is no over hang just use the same hight above plate of the common say 4 1/2” for the seat That would be the center of the valley the two ouside edges of the valley would be lower because of the side cut of the valley
Phenomenal. I’m intrigued if you ever cut say a birdsmouth that’s not in quite the right place. Guess years of experience have taught you all the little ways to avoid. Interesting point first about the building being level, true and square at the gable, and what to do if not (and how much you can get away with and still work round)
Good job. Spot on. 👍👌 Did you use a single valley rafter as you are sitting on the ashlar wall. Just say it wasn’t there would it be a double? Nothing can replace the beast. When it’s needed. (Corded circular saw) My top tip this winter you can always take a layer off if you get hot 🔥 but you can not add it if you haven’t got it with you. Keep warm.
Afternoon robin, as a time served carpenter/ joiner, I applaud your articles . Why disclose your knowledge on utube? I recently came across a bloke claiming to run a job, on which I was approached to quote a cut roof, claiming he was made redundant . Then went into construction ? Prey tell me what is your take on the absolute non existence of any standard whatsoever on the site? Either it be a porch or hospital ? I’m very concerned at the lack of qualified people claiming their opinion counts ? As we know it’s not fact ? Their opinion ? No wonder the industry is in such a shambles since I began in 1982 ? What is there in place to rectify this ?. Kind regards paul
Great piece of work. Would be good if you could use a whiteboard or similar in your Q&A sessions with ED, just to sketch out this and write down the calculation for people to follow the math. Some people I have found struggle to follow unless they can visually see the calculation process written down.