My first complicated roof - only my small question

[gjburkett]

Well, I think I've finally got the hang of the roofing tool. I like how smart it is, but it can still obviously be better, especially for us residential guys. :wink: Anyway, I'm working on a project at work where we draw in 2D using AutoCAD. I thought it would be cool and very helpful to me and my Revit training (since I'm learning on my own) to see if I could model the roof since it's pretty complicated. I was pretty successful at it except for one small thing. It seems like Revit can't see that I want another pitch on the roof in the area over the stairs. Look at the pictures I've attached to see what I'm talking about more clearly. I've added some red areas pointing to the area at interest. Anyway, does anyone have any idea how to achieve this? :-? That would be greatly appreciated. Thanks in advance. :razz:

P.S. I think what I'm going to have to do is make a separate roof for that particular area and join the geometry, but I wanted to see if anyone else had any other ideas.

[Scott D Davis]

honestly, it looks like the revit roof is correct. Adding another 'facet' isn't going to get you anything.

There was an example of a similar roof here before. When you add the etra piece, the top part of the roof that extends to the flat ridge ends up being a 'warped' surface. It's very slight, but it happens. In the field, the framers simply allow the each rafter to change angle slightly as they extend from ridge to valley. The plywood sheathing then is nailed down to conform to the curve. It's so slight that it's barely noticable.

[gjburkett]

I know, I'm not saying that Revit's roof is wrong. I'm saying that there are two solutions to this roof problem and I didn't get the one I wanted. Both can be done, but we want it to look like the way I drew it in 2D. It's not a big deal or anything, but it does look a little better than the more "basic" way (to us anyway). The framers may do it the "basic" way out in the field, but we still want to get it down on paper the way we would like it to look.

[Scott D Davis]

Totally understand. Revit's roof tool creates 'plane' roofs, in which the surface is flat. Your 2D example creates a 'facet' which actually has a surface that is not all in the same plane, and therefore Revit doesn't like it. If the ridgeline were sloped, then it would work. Since its horizontal, and the valley is sloped, the plane between the valley and ridge is warped. You can approximate this, or model it with an in place family roof.

I'll see if I can find the example here in which this exact same roof concept was discussed.

[J. Grouchy]

Doesn't it seem like one should never really trust a sloping roof drawn in 2D? There's so much opportunity for user error no matter how experienced one is.
I'm not saying the Revit (or any other 3D software) roof is perfect or always what you want, but I would tend to trust being able to build a modelled 3D roof over a drafted 2D one.

[gjburkett]

Doesn't it seem like one should never really trust a sloping roof drawn in 2D? There's so much opportunity for user error no matter how experienced one is.
I'm not saying the Revit (or any other 3D software) roof is perfect or always what you want, but I would tend to trust being able to build a modelled 3D roof over a drafted 2D one.
Not really. And again, I'm not saying Revit is wrong. That's not what I meant with this thread. I'm saying there are two ways to build that roof and I was wondering how to achieve the second method since it's more appealing to us eventhough it's more difficult to build. As for what is drawn in 2D, it's not wrong either. You're right, there is a chance for user error since it relies on geometry and how good the user is at it, but there are certain "checks" you can do to make sure it's correct. I won't go into any of that since I'd be here all day, but I hope you know what I mean.

[gjburkett]

Here's my first stab at trying to make it the way we want. I made it a separate roof and joined geometry like I mentioned I would. Still not exactly what we want, but hopefully you'll find that thread for me so that I can relate what was discussed there. I've searched before I even posted this, but couldn't find anything.

Is it safe to assume that the Revit creators are aware that the roof tool needs a make-over? Maybe all they need to do is add a "residential mode" and take notes from Softplan, VisionRes, Chief Architect, etc.

[tamas]

You could add a small triangular roof as a "dormer" with the desired slope and cut the big roof under it.

I think your roof can be built with planes. No twisted surface is needed here.

[Gadget Man]

If what you are looking for is represented on the first picture, the second picture describes how to achieve it... ;-)

[gjburkett]

jetistart, that's a good idea and need little cheat. Unfortunately when I tried that, I got the "Can't make footprint roof." message. :?

[SkiSouth]

Your straight line is too small is what that error indicates. Use 1" rather than 1mm. See if that doesn't clear it up.