'Z' purlin orientation in beam systems

[ksawyer.75753]

Firstly, appologies if I am duplicating a current thread but searches didn't find what I'm looking for.
I have a pitched roof using 'Z' purlins on rafters, fairly simple stuff. My problem is that when modelling beam systems on opposite sides of the roof apex, all my purlins face the same way. I want the top flanges to face towards the ridge.
I have tried creating my beam system shape in different orders and even tried mirroring one correct system about the ridge but to no avail.
I have set up reference planes at the top of the purlin line in all pitches and located my beam systems to each.
Can anybody please tell me how to reverse one system as a whole or do I need to do separate purlin members? I'd prefer to keep the system as it's easier to manipulate and the architect ensures that I will need to do lots of manipulating after creation.....
Cheers.

[jabamax]

Know the problem.
Here is the fix.

It matters which direction the span direction is drawn.
If you draw the span direction from right to left, you will get result A, if you do it from left to right, you will get result B.

Makes it hard when you use the rectangle tool.

Delete the span direction boundary, and redraw taking note of which side you started from. If that doesnt fix it, delete it again, and start from the other side.

[ksawyer.75753]

Too easy! Thanks for that.