thanks for all the posts everyone.

Will, I look forward to reading the article. That reminds me of something....

Gabel, that is a good post. Thank you. The HAP stuff is kinda what I was talking about. Your info is helpful.

You guys are right about the building corner. As the discrepancy in pitches magnify the hip falls further and further from the building corner. It does sometimes look funny when it crosses a plate 1/2' from the corner!

I feel confident about doing all this with no overhang including irregular plans, different pitches and such. More tinkering is definetly involved with the overhang aesthetically and mechanically.

Back to the drawing board..... I might just have two trusses as bmike suggested, put a ridge in there, equal pitches, equal overhang, Voila! but is fun to mess around with it.

mo -

while it will be a creative roof to get the plan and center pin to work, what i like about the 2 truss concept is that it really helps lessen the outward thrust on the corners. not something that can't be solved - but it is an elegant solution and will probably allow you to keep wood to wood joinery in all cases and not have to go with some hidden tension steel in the corners (or really long bypassing tenons - that could pose tricky.

the other nice thing about the 2 trusses is you have the option to get some bracing to a ridge to stiffen the roof laterally along its length. certainly a hipped roof triangulates along itself - but i've experience hipped roofs being a bit jiggly until the sheathing gets applied. adding a few braces can't hurt.

good luck, and my offer still stands. send me an email if you want me to take a peak at some sketches or want to see something dropped into sketchup or hsb.

-mike

hey mike, yes while I have been thinking in geometric design you have been thinking about it working. thank you. what you say makes good sense.

I appreciate you offer as well. I might be taking you up on it soon.

I have messed around a little. I took some advice on this thread and decided to build the roof first, then set the plates and posts. This one does not have an equal overhang but at least the hip falls in the corner (except for a little offset for an equal depth backing). This seems a little stronger than working with an equal overhang which then makes the hip fall out of the plates converging corner. Granted the plumb cuts of the rafter tails are different heights I guess you could leave fascia off or make the height of the fascia to the greatest plumb cut.

Ill try the equal overhang next.




p.s. Im trying to get all I can out of this software before a student license runs out. good stuff.

mo -

looking good.

to solve the gutter board / plumb cut height issue you can always reduce the tail that protrudes beyond the plate. check out the old heartwood / sobon shed for how it might work. you can make a consistent height with 2 different details - and if you make this a feature and do some creative detailing it could be a nice addition.

the other option to consider, instead of a traditional king post truss, is a sloping rafter hipped truss.

here's a pic:





basically set up your hip and a rafter in line with it. this becomes the truss. the example is uber complicated... but the idea might work in your case, esp if you have straight bottom chords and king posts. (we added queen posts to help control the size of the curves)

-mike

actually the hip is in the corner. the backing is offset. mispoke in previous post.

hey mike, just noticed your post. Wow! I like that. How do the "interior" hips pass each other? that cripple looks like that was a headscratcher too. Is this built?

mo,

Use a square tailed fascia to eliminate different plumb cut heights from one side to the next. I think it looks better anyway and it looks super cool on the hip tail when it's irregular.

mo -

never built, client got wet feet when we were ready to sign engineering contract.

there are 2 trusses that run parallel to each other.
the other 2 hips would be 'broken' at the truss hips.
deep housings and probably a metal strap over the top.
there would have been a curved reduction at this location to get 1 of the hips slightly smaller than the other, or a stepped housing to keep all the hips looking the same.
piece sizes are all 10x thick so we had plenty of room to get housings, etc. curved pieces were 8x thick to house into the posts and rafters.

we did quite a bit of 'freeD' modeling and engineering analysis on it. was going to be a 'hat' on a conventional stick and stone wall of a house, RF fir to control the shrinkage and curves. plenty of embedded steel (mainly due to the curves). would have built the 2 trusses on the ground, set them, and filled in the blanks.

owner bounced back and forth between us and another company. fired the original architect, came back to us later, asked for a 'simpler' solution, we did more work, then wanted the deluxe package, then flipped out and buried the project.

he wanted to be wowed and didn't want anyone to pull punches. we didn't. he flinched.

what software? looks like autocad... what are you driving the timber portions with - or are you using solids?

I think it's Cadworks.