Hip gable framing?

[ScottA]

I was wondering if anyone ever framed a roof like the one in this photo could tell me the best way to go about it?

It's the part on the far right over the bay window I'm wondering about.

Scott

[FrankInWI]

I always wondered about that type too, and recently seen a picture of trusses in place that end up looking like that. I wonder if it wasn't in the Wagner framing book so heavily relied on in this forum ( a fantastic book by the way! .... our pre-work and on site bible.  

[Jens]

The roofline shown is called a dutch hip, dutch gable, or simply Dutch roof.  It could be framed in a few different ways, and I'm sure PEG could tell you another way.  

Build the gable end wall, with a rafter on top of it.  Measure the distance from the gable to the end wall, to find the length of your Dutch common (end king common on a hip roof).  Use any of the formulas, or a construction calculator, or rafter table to find the length of the rafter, and cut it as if the gable is the ridge board.  Take this Dutch rafter, and place it next to the end common rafter that sits atop your wall, scribing the ridge cut location onto the common rafter.  This is where the center of your hip rafter will sit.  

Pull a measurement from the top of this mark, to the corner of the walls.  Take this measurement to your hip stock (which must be at least 2" wider than common rafters), and mark for the ridge cut (don't forget to use the hip scale of the speed square).  Copy this mark on both sides of the rafter stock.  Set the bevel of your saw to 45 deg, and the blade so that it cuts on the waste side of the rafter, make the cut.  Turn the rafter over, and repeat, you should now have a double beveled end, with the proper ridge cut.  have someone hold the measuring tape at the point, on the top of the rafter, and pull out to expose the rafter length you measured previously.  Pinching your pencil, to your tape at the proper measurement, use the whole thing like a big compass to scribe a mark across the whole board.

Now for the seat cut.  The way I do this may be different from other people, but it is the easiest, most dependable way, that I have found, that also involves the least thinking.  I grab my common rafter, and extend the line of the plumb part of the seat cut all the way up the rafter.  Next, I measure the distance between the hell cut, and the top of the rafter, along this line.  This is how high above the plates the roof plane sits.  If I am double beveling the tops of the hip rafters (much nicer looking for exposed rafter tales, but not altogether necessary), then I do this first.  Snap a chalk line 3/4" (or half the rafter thickness if different) inside of the top edge of the rafter, on both sides, and rip off the corners.  Measure down from this new edge along the plumb ( done easily with the speed square set at proper pitch, reading the number from the blade), and make a mark.  This mark is now the corner of the seat cut, and at the same height above the plates.  Mark and cut the seat cut.  If you don't bevel rip, do the same from the top edge of the rafter, but subtract 3/4", to drop the rafter so that the roof stays straight.  

If everything has gone right, and I haven't got you totally confused, your hip rafter should now be cut properly to sit where it needs to be.  Once both hips are up, install a 2xwhatever between them to act as a ledger for the Dutch rafters.   Now cut all of your Dutch rafters, but subtract the  1 1/2" from the plumb to make up for the new ledger.  

Frame the overhang of the roof, the same as you would a regular gable, but the ends of the fascia boards rest 1" above the sheathing of the hip (so that roofing can be installed).  

BTW, fill in the rest of the rafters in the hip portion, and sheath before framing the overhang.  

I hope that is clear.  You may need to read a few times, sometimes I can't explain things the same as I can build them in my mind!

Check out the book, Framing Roofs, from Taunton Press, it has another way of doing this too.

If you don't want the wall underneath the gable end to be load bearing, double up the last common rafters that the hips attach to.

[Jens]

Here is a quickly drawn framing view, that might explain it more.  Not how the hips attach to the last common rafters.  Walls have all been removed for clarity.

[ScottA]

Fabulous! Thanks alot. I think I get the picture.

Scott

[MountainDon]

Architecturally interesting. Also interesting to see how it's done. Thanks hobbiest.

However I will pass on it. I just don't want to get into cutting angles with the 26 ga. steel roofing.

[ScottA]

I see this as a compromise. I wanted to give some protection to the wall that a hip roof overhang offers but I need the gables for windows and the loft area. Plus I think it look cool. Didn't think it would be to hard to do. Hobbiest do you think this makes the roof stronger? I always heard gable ends where more prone to wind damage.

Scott

[PEG688]

   A hip roof is about the strongest roof going , domes may be a bit better .

 The only" benefit " to a dutch hip is looks , if you happen to like that look . Hobbiest is right ,  there's always another way , his way is fine and he did a fine job of showing / explaining it   as well.
 
The "protection " you mentioned is very slight , but yes it does some what add protection , but a hip roof has less leak prone areas , is easier to frame in ways , and uses less material than the added "dutch hip" detail.

[ScottA]

Would it be ok to frame the gable wall within the rafters? Here's a rough sketch up.



I was thinking if the rafters where doubled they should be able to support this small gable wall. The ledger (collar ties) for the hip portion of the roof would be doubled as well to build the wall on and attach the rafters to.

[PEG688]

  It would work but you'd need engineering to get some thing like that permitted , at least around here, PNW.

  What would you be doing framing that in say 4' back inside the gable wall?  Generally on a dutch hip a girder truss is put in a back framed to from the gable end lower wall.

You'll need to think through the ceiling area that would result under that dutch hip as well.

It can be done , BUT if your using one of John's plans you'd have some issues to deal with as a result.

So I may not be following your plans / design you'd be building a dutch hip into. Generally they are added to lower pitch building like 5 / 12 and under with wide eaves.

So could you elaborate on what plan your using / leaning towards

[ScottA]

As far as plans go I'm making this up as I go but basicly the shell will be framed like one of Johns plans. 16' wide with a 12/12 roof. Small loft at each end supported by beams across the span not the walls. The dutch gable sits 2' back from each end and extends out for a 2' overhang all the way around. I want to use the 2' space under the dutch hip roof for storage cabinets in the loft. so I'd rather not bring that gable wall down to the loft floor. I don't see why it wouldn't work. Double rafters on the ends, 1 rafter to hold the gable roof and one to hold the wall weight and hip roof. The side walls are 9' high and the overhang sofit will be 2' lower than that. What issues do you see?

[ScottA]

Maybe this will help clarify my confused explination.

[PEG688]

 #1 would be code -ability / permit ability , without a engineer signing off on it.

It would work , IMO , BUt there would be issue that I'd have to see / figiure out either on paper and or in the field. Some of which may , or may not bother you.

It will look "odd" IMO a dutch hip witha 12/12 but that's just my opinion , not wrong mind you , I just don't think I'd like that combo.  That doesn't mean it "wrong" if you follow me.

[ScottA]

It will look "odd" IMO a dutch hip witha 12/12 but that's just my opinion

Well I've been called odd before so I'm used to it. Nothing about this design is normal I like to be different/difficult I guess.

[PEG688]

Maybe this will help clarify my confused explination.

That double rafter is back further than 2' , so you hip would be "odd"  a true hip needs more similar corner set back or the hips look "ODD" .

Of all the roof designs the three assist to screw up , IMO , are a Gambrel (barn style) , Mansard , then the hip . Very easy to get the proportions "off".

  If you can do a sketchup of the roof I'll think you'll see what I'm saying, then again maybe you'll like it even more , beauty is in the eye of the beholder , they say.   

[ScottA]

Looks like I confused you even more that is hobdiest drawing from before I just borrowed it for a quick explination. The double rafter would be the first one back from the end wall. (Rafters on 2' centers) It would look just like the picture in the first post except on a 12/12 pitch

[PEG688]

Looks like I confused you even more that is hobdiest drawing from before I just borrowed it for a quick explination. The double rafter would be the first one back from the end wall. (Rafters on 2' centers) It would look just like the picture in the first post except on a 12/12 pitch

No I understood BUT when you move that  first "pair" out board  that where the shape goes to hell in a hand basket. So one totally effects the other.   

[ScottA]

Now I'm confused.  I'll study it some more.

[PEG688]

Now I'm confused.  I'll study it some more.

Draw up that gable end say 1/2" to the foot and "see " that roof pitch with a dutch hip , good design exercise if nothing else.

Class will re-convene at..............