Roof Hosting Beams

[kROSEMAN]

Hello All,

I am having a problem hosting a beam to the bottom side of a roof. The roof is a 3/4" plywood sheathing that has multiple different slopes. I was able to host a beam on one of the sloped faces but I am unable to pick another face to act as the host. The roof has (4) sides, (2) sides are perpendicular to each other the other (2) sides are at different angles. Each corner has a B.O.D. of different elevations, which ends up creating sloping ridges and valleys. I've tried creating the (4) sloped panels of roof as one roof unit with the sub elements edited to their respective B.O.D. elevations and as separate panels. Either method was unsuccessful in allowing the roof to host one of the beams. It was only after creating the roof into seperate panels and keeping the troublemaker panel flat, placing the beam hosted by the offending panel, then modifying the sub element corner B.O.D.'s to get my slope for the beam. Has anyone else experianced this kind of problem? Have a better solution?

Thanks,

Kyle

[tkunsman]

So it sounds like you are modeling the roof and the structure in the same file?

It seems like you might be using the "Pick Plane" option on the Set work plane. While this might work I sort of feel that having named reference planes that match the slope of the roof with a plan looking down at the whole roof might be a better option.

Care to share a picture of the roof?

[kROSEMAN]

tkunsman,

That is correct, I am modeling the roof as part of my structural model, only because of the complex slopes of this roof. Like you I usually use reference planes that match the slope, but in this instance the roof slopes in 2 different directions per sloped face. Because of the complex slopes, which there are (4) of and none of them are the same I am modeling just the structural sheathing of the roof system for hosting the framing members. The reason for the hosting is that we want the spacing of the framing members to be in line with the slope. The framing members themselves, a combination between wood trusses and joists will be leaning over to match the slope as well.

At any rate after spending much time on Friday trying to work this out virtually I had a theory that the numbers that were provided to me for the sheathing B.O.D. elevations were off causing a very slight twist in the roof that I had modeled. After doing a couple of sketched in ACAD to verify the heights and rechecking the arch'l model for myself it was there that my theory was proven. The numbers that were provided to me were rounded to the nearest 1/8" and after changing the units to 1/256 rounding the discrepancy was located. Thanks for your help, I will post a picture a little bit later.