Sloping beam system?

[patricks]

Is there any way to create a beam system that is not flat? I actually need a beam system where the joists run perpendicular to the slope, so each joist is flat, but the height of each joist changes. Is there any way to accomplish this?

[dhurtubise]

Pick the beam as the support in 2008.
BTW congratulations ;-)

[patricks]

I tried picking my sloped girder joists as the supports, but it put the line down flat on the finish floor level. The girder joists' reference level is well above the floor, with different start and ending offsets, so I can't figure out why it would put a beam system boundary line down on the floor level.

[whittendesigns]

It sounds like you're doing something like purlins maybe?

What I have is a line based setup.

I place a reference plane on the surface of the beams/rafters/roof. Then in plan view I place the lines, then use the pick tool to select the lines and use the named reference plane that you made as your work plane.

Slight problem maybe is I haven't tried this with beam systems. I gave up on those long ago because I couldn't figure them out. So this is a one pick, one purlin thing, so it may be tedious.

[patricks]

I was trying to use a beam system because the building is 500 feet wide, with open-web joists spaced at 5 feet, so there are 101 joists across the width of the building, each one slightly higher than the previous as you move towards the roof peak down the center of the building. There are sloping girder joists at 1/2 : 12 roof slope, and then the roof joists run perpendicular to those (parallel to the roof slope).

I may end up just modeling the joists in a few bays. I have 18 structural bays which would end being over 1800 joists if I modeled them all, which is probably way overkill.

[Scott D Davis]

I tried picking my sloped girder joists as the supports, but it put the line down flat on the finish floor level. The girder joists' reference level is well above the floor, with different start and ending offsets, so I can't figure out why it would put a beam system boundary line down on the floor level.
make your columns, and then 3D snap yoor beams to them to get the slope you want. Then use a beam system and use Pick Supports to outline the beam system. the sketch may go on the floor, but once you finish, it will conform to your beams. Then the new RAC 2008 roof tool can use Pick Supports to conform a roof deck to the beam system.