I'm a Framing Contractor in New Jersey for the past 19 years. I've cut many different types of roofs befor and up until about a year ago started to use a calculator.

I use a Construction Master Pro Tirg Plus III.

I've been participating on the Rough Framing Forum for The Journal of Light Construction for the past year.

There's has been many conversations about roof framing that I brought up because that is my favorite part of Framing.

We've discussed many ways of framing "Bastard Hips" or "Irregular Hips".

90° walls with two different pitches. Maim roof(Front to back) can be 8/12 Pitch. Side Roof can be 10/12 pitch.

There's alot of discussions about Formulas for these roofs such as.

Figure Pitch of Hip.
Hip In Plan View.
Hip/Valley offset to equal overhangs and Fascias.
Hip Lengths.
Cheek Cuts.
Backing Bevels.
Hip Drop.
Plate height Difference to equal overhangs.
Jack Rafter Difference for both pitches.
Plywood Angles.
Different overhangs when Hip sits on the corner.

I know Timber Framing is different than Stick Framing but to figure out rafters in the situations I listed above or any Roof situation has to be the same wether you use just your Framing Square, Calculator, Scientific Calculator using all Trigonometry, Construction Master Calculator With Trigonometry in it.

The Construction Master Calculator has a lot to offer. For example, 8/12 Pitch and 10/12 Pitch Roof. A few different ways.

8 [Inch] [Pitch]

12 [Inch] [Run]

10 [Inch] [Conv][Hip/Val]

Press [Hip/Val]Twice Returns - 17.325" (Hip Length)

Press [Hip/Val] Returns - 27.50° (Hip/Valley Plumb Cut)

Press [Hip/Val] Returns - 62.50° (Hip/Valley Level Cut)

Press [Hip/Val] Returns - 38.66° (Plan View Angle 10/12 side)

Press [Hip/Val] Returns - 51.34° (Plan View Angle 8/12 side)

Or to figure the Hip/Valley Plumbcut.

10/8 = 1.25

Press [Conv] [Tan] Returns - 51.34019°

Press [Pitch]

12 [Inch] [Run]

Press [Diagonal] Returns - 19.20937

10/19.20937 [=] [Conv] [Tan] Returns 27.5005°

Or This.

10/8 [=] 1.25

Press [Conv] [Tan]= 51.34019°

Press [Cos] x 10 [Inch] [Pitch] Returns - 27.50°

Or This.

51.34019 [Pitch]

12 [Inch] [Run]

Press [Diagonal] Returns 19.20937

Press [=] [Run]

10 [Inch] [Rise]

Press [Pitch] Returns 27.50°

These are just different ways of using the CMP calculator.

I have alot of Formulas on the CMP calculator that I've come up with to simplify Irregular/Bastard Hip Roof situations.

I found a thread here by Dave Gee, "Hawkindale Angles".

Dave and Ed Levin discuss Hawkindale's Formulas.

It's a very interesting thread.

I'm going to try and find out more on Hawkindale's Formulas.

Do all Timber Framers use Hawkindale's Formulas or does everyone use their own?

I would love to go to a Timber Framing seminar on Roof Framing.

Sorry for the long post but I have a great passion for Framing and what I do for a living and I'll never stop trying to learn something new.

Joe Carola

Welcome Joe: I went to the JLC trade show held in RI last April with a friend and it was great. I got a lot of useful information there and learned a lot. Thanks for that.
There is a Eastern Conference coming up this fall in Canada. You should try an attend if possible, even if you're not a member of the guild. There is a whole list of speakers on different subjects and you might be able to meet Ed Levin and others had discuss all your questions in depth face to face.
There is lots of information here on this forum and in the achives about all sorts of subjects, around timber framing.
You've posted some questions here (which is ok) but maybe they should be posted under timber design or timber engineering where the moderator(s) and/or others can help you more. But anyway, welcome. and have fun with your research. Jim

Jim,

Thank You. I just posted it in Timber Engineering.

Roof Framing for me is still the most intriguing part of framing.

The conference in Canada sounds interesting. Can you give me more information on it?

Thank You Jim.

Joe Carola

Joe:
I'm going to send you an email with a copy of one of the pages in our monthly newsletter that has some details about the conference and speakers.
I can't seem to find this same info on the TFG home web page. And I don't understand why it isn't there. (Mr. Moderator are you listening? or if it's there can you point Joe to it?) The only mention of it, that I can seem to find, is in the calendar or conference section and it provides a link to the hotel's web page, but I believe it's all booked up for that time frame. I think I'll be staying somewhere else as I haven't booked for it yet.
If you have any trouble opening the email with the jpeg embedded in the email, let me know and I'll sent it as an attachment.
Jim

Complete conference details will be available on the website before the end of this week.

Brochure/Flyer goes to the printer tomorrow, after the final proofing, which we are doing today.

Thanks for the update about the details, we're all looking forward to them.Jim