hip (not valley) cheek?? cuts

[speaker]

It's already Christmas morning, I just stumbled on to a question for one of you guys, while I was planing.

Example:
2 walls running parallel, then they both angle off at 45 o to form a outside and an inside corner.
the ridge meets in the middle, at the corner.
the valley rafter will get 2 - 22.5 degree cheek cuts
(forming a 45 degree point) on the plumb cut

but the hip ??, it would go to figure that the plumb cut that meets the ridge would have 2 - 22.5 degree angle cuts , creating a concave situation.

I helped frame roofs for 6 years (a while ago) but never remember a hip with a concave angle cut!.

Do you off set the hip/valley 3/4" to either side?

Thanks (Merry Cristmas)

[Joe Bartok]

This sounds interesting, any chance you can post a diagram?
Meanwhile, here's a thought that may help: Treat a hip as if it's and "upside down" or reversed valley. Any miter lines, blade angles or cuts near the foot of a hip rafter are located near the peak of a valley. Similarly, layouts or cuts near the hip peak are located at a valley foot.
Speaker, If you can manage a drawing, I'll try to get back to you today. If I can't, I won't be able to respond until the New Year.

[Joe Carola]

Speaker,

Are you talking about a walk out bay?

[Dragon]

I wonder if Joe frames those the same way I do.

[speaker]

Sorry, I haven't checked back in a while, I will post a drawing, thanks for the replies, but you will see what I mean.
by the way Joe do you centre your hips on the corner, or off-set them

I will do the drawing A.S.A.P.

[speaker]

I did a quick Illustration, hope this helps clear up what I am trying to ask
thanks

[Joe Bartok]

Ooops! Almost missed this post. I'm limited with regard to computer internet time today, but have downloaded both images and will try to find time to go over them later today (or tonite).

[speaker]

joe (corola) looking at your diagram. Do you usually offset your hip, or run it directly over the corner

[Joe Bartok]

Speaker, I had a look at your pics last night. The hips and valleys are pretty much where I thought they were from your written description. But your first post seems to describe a negative angle ("concave situation"), and for the life of me I can't see where that's happening (probably due to a dead short in my brain).
Acute angles that form "feather edges" crop up constantly on the joints created by intercepting members in a timber framed roof, and the math is geared toward eliminating these situations. But if I'm reading your first post correctly, this isn't just a simple acute angle in question.
Looks like I'll have to sit back and pay attention, and perhaps a post by someone else in the forum will make things clear.

[speaker]

I don't know, the dead short could be in my brain, that's why I.m doin' the askin' lol
well let's see..., if you notice in my version of a "magnified view", the blue lines are the top of the hip where it meets the 2 ridges intersecting. If I were to make the cheek cuts so as they would fit snug around the protruding corner (ridge intersection) it would require 2 concave 45 o angle cuts.
Again as I mentioned on my first post, I do not think that a concave cut is the answer, so is the intersection of the 2 ridgeboards cut at different angles (instead of just 2-45's) to allow a off-set of the hip rafter.

thank for the help!

[speaker]

this illustration is not to scale, but I hope that you can still get the gist of what I'm gettin' at. the blue area (as noted) is the material removed from the hip and valley not the ridge's (I know that YOU know that, but it may look confusing) and as far as I can see, all of the angles should be cut at 22.5 o

so to reiterate, the cheek cuts on the hip would have two (negative)
22.5 o cuts in order to form around the ridge corner, and as I mentioned earlier I can never remember assembeling a hip that was cut this way

I hope this clears up what I am trying to say
thanks...

[Joe Carola]

Speaker,

If you view your last drawing as if it were a 45° bay in plan view and the areas marked ridge board were your wall plates to butt those wall plates together would be 1/2 of the 45° angle which 22.5°. If you looked at the area marked valley and took a 2x4 and cut 22.5° cheek cuts on it and slid it into the back of the plates they would fit perfect. Now do the same where you have the area marked hip but just reverse the 22.5° cheek cuts and they would fit perfect.

Now look at where you have the areas marked ridge board and view them as if they were the fascia you would miter the fascia at 22.5° for them to buitt eachother and the area marked valley would be viewed as the hip overhang with cheek cuts at 22.5°.

If you view thing in plan view or snap out a roof on the deck you will have all your angles you need just because your going to be cutting rafters no matter what pitch you have the cheek cuts will remain the same angle as if it were flat on the deck.

For a normal hip running at 45° you would cut the hip cheek cuts at 45° on the top and 45° on the bottom and you could cut the fascia at 45° to fit.

So where you have your hip and valleyin your drawing those cheek cuts would be 22.5° as you said in your last post.

If that were at 30° your cheek cuts would be 15°.

I hope this helps a little so far.

Joe Carola

[Joe Bartok]

Between the new drawing and t'other Joe's description, I "get the picture."
Here's a drawing of how I was envisioning the situation. Not exactly the same scenario, but this is why I had a bit of a "blind spot". It's not to scale, hidden lines are omitted for clarity, and the angles are of course distorted in the side view as well as different in value from the 22.5° due to being projected to the bottom face of the hip. But, that's where my "blind spot" was; there actually would be a concave angle in this case.
Different than 2 × framing, but there are similarities as well. (And hopefully this isn't getting off topic). Anyway, I've learned something new, just what I signed up for.

[speaker]

[quote="Joe Carola"]Speaker,

For a normal hip running at 45° you would cut the hip cheek cuts at 45° on the top and 45° on the bottom and you could cut the fascia at 45° to fit.
[color=#336699]
[color=red]Joe C, thank you for your help, I understand your analgies. I guess I just never assembled a hip that came off of a 45 o ridge intersection. As for the quote above, look at my new drawing, you will see where the hip meets the facia (red circle, blue line) is that what you are refering to when you said, "you could cut the facia at 45o to fit, and if so, do you cut your facia at the corners like this, or just butt them. I had always just butted them

Also, where you see the "orange circle" do you cut cheek the inside of the hip (concave, in the same fashion we are discussing regarding the hip, in my original question) so as it forms around the outside of the wall (on the tail cut) or do you just make a square cut (as indicated by the perforated blue line, inside the orange circle)
but you answered my question, and I will cut the 2 - 22.5 inverted cheek cuts on the hip, where it meets the ridge
thanks again!

Joe C, from what I can tell your drawing indicates a birds mouth cut sitting on top of a wall which is angled at 45o. I'm really not sure, I am sure it makes sense, and do appreciate the time spent, but I don't think that I understand it, it looks to me like what you have drawn is a bridge I will cross if I ever have too (lol)

On your drawing you have (at the top) C5 backing angles is this the alternative to a hip drop

[Joe Carola]

[color=orange][quote=Joe Carola]Speaker,



Joe C, from what I can tell your drawing indicates a birds mouth cut sitting on top of a wall which is angled at 45o. I'm really not sure, I am sure it makes sense, and do appreciate the time spent, but I don't think that I understand it, it looks to me like what you have drawn is a bridge I will cross if I ever have too (lol)

On your drawing you have (at the top) C5 backing angles is this the alternative to a hip drop


I know your directing the question at Joe B but I hope Joe doesn't mind me answering because I can't sleep (sorry Joe). His drawing is correct at the birdsmouth. If you wanted exposed rafters that would be perfect to cut but for cutting that hip if not exposed you don't have to cut the inside and outside V cuts you can cut your seatcut straight through and the outside heel cut just cut straight.

If you were to cut ther V out that that would slide your hip up towards the ridge whatever the depth is so you would have to cut that amount off the plumbcut at the top or it would be to big.

His picture with the backing angles is correct and you wouldn't have to drop the hip if you bevel it just like a regular hip..

As for your question about cutting 45° on the fascia. I've done them both ways. Some GC's that I frame for want 45's some don't . When I do it for myself I'll 45 them becasue when we put beadboard soffits in it looks nicer because we're cutting the soffit at 45°. Some additions I do the existing has square cuts so we have to match existing..

Joe Carola

[speaker]

Thanks J.C.

My rafters will be covered, so I will not have to cheek cut around the outside wall, and yes I see how you would have to be careful regarding the distance of the rafter when performing these cuts.

I figured that this was the function of the "backing angles", but just wanted to make sure.

As far as the facia cut at 45o, does it really matter what kind of soffit your installing. I mean after all, it will be completely covered?

Now J.B.'s illustration(s), in the bottom pic it looks like the hip is resting on a wall with a top plate that has a 45o, I'm not sure if I am reading this correctly or not, and do not see where all these angles are coming in to play

I have done another "not to scale" hip rafter extending over the wall (at 45o) I guess I just don't see any difference other than cuting the cheek cuts to form around the corner (if the rafter were to exposed)

but again thanks for both of your replies

[Joe Bartok]

I was dubious about posting that last image, fearing it would cause more confusion than answering the question. Any drawings I post are "stock" images off my hard-drive, they are no trouble to create, and it would actually have taken more effort to edit out the irrelevant information, so I left everything as it was. All it was intended to show was that a concave angle is possible. If you imagine the plumb line being moved to where the pocket is on the hip rafter, and cut at the deck angle, you will have what Joe C. descibed in a previous post. And Joe, don't be "sorry" for answering, even if any questions are directed at me. My experience with framing in general is limited, and you've probably forgotten more than I'll ever know. One reason I registered on this forum is to fill in the gaps in my knowledge, and I'm always interested in questions and answers by one and all.
As for the angles on my drawing: The deck angle shown isn't necessarily 45 degrees. The deck angle and the two pitches can be any value, the actual numbercrunching to determine values is done by a program. The algebraic names shown indicate the location: R4 is always the deck angle projected to the bottom hip/valley shoulder to create a miter line, A5 would be the saw blade angle along this line, R1 is always the hip/valley pitch angle, ...etc. And yes, backing angle C5 is the bevel required to bring the planes of the roof in harmony with the hip/valley. In the case of valley rafter, with a vaulted cathedral ceiling where everything is visible, without the backing angles there would be a space (we're talking about three to four inches here) between the ceiling and the rafter.

[Joe Bartok]

In case anyone can't reconcile anything I've posted with my diagram of the hip rafter, there's a good reason. It's the wrong image. :oops: To get the concave angle everyone else is talking about (except me!), the drawing should have been of a hip meets POST. Or, the hip rafter would have to be a valley, meeting walls intercepting at an angle greater than 90 degrees. Everything would be the same except the angles for the housing near the rafter foot would be reversed.
Sorry about that, guys. Next time, I'll try taking my head out of my a$$ and pay closer attention to what I'm doing.

[Joe Carola]

Thanks J.C.



As far as the facia cut at 45o, does it really matter what kind of soffit your installing. I mean after all, it will be completely covered?



They wont be completely covered when you use a 1x8 or a 1x6 fascia and 4" gutter and using beadboard soffit with 45° angles looking up at the soffit you will see the 45° angle on the fascia and it looks nicer then seeing the squarecut endgrain.

Joe Carola

[Joe Bartok]

Here’s a roof system that may be of interest, and this is why I thought it best to get a diagram earlier on showing exactly where the "hips" and "valleys" in question were located. The hip rafters (or are they valleys?) have concave angles at the foot, though not as acute as in the original question that started this thread. The combination of pitches was of interest to me for another reason: the values returned by my angle calculators for the deck angles, angles on the rafter shoulders and angles on the roof planes are affected by the large initial value for the deck angle.
Note the backing angles in section. These cuts would typically create either a ridge on a hip rafter, or a trough on a valley. But on four of these rafters, the bevels are a hybrid of both hip and valley, and there would be a significant loss of both material and hence strength. Also note the angles on the roof planes in the diagram on the last page; the values designated 90 – P2 would normally both be located near the eaves for a hip rafter, or near the ridges on a valley.
The actual rafters were 6 by 22 glulams, simply cut to length at the plumb lines at both ends, and fastened to a kingpost at the peak and posts at the feet with hardware. Nor were any backing angles cut on the upper surfaces. But my program calculated all of the values whether they were needed or not, so I made a 3D model of the roof. The geometry of the model; the backing angles, the angles on the hip shoulders, and the angles on the roof plane, actually conformed to the values in the table. So, what are these rafters? Hips? Valleys?