Roof planes

[Joe Carrick]

No argument here, potato, potato, tomato, tomato, it depends on how we work.

Exactly! I almost always use the Auto Roof Plane Tool. I've never had a problem using Manual Roof Planes but the automatic tool is faster for me 95% of the time. In addition, if it doesn't work as I expect then it gives me a very quick tutorial on what I've done wrong in the model. BTW, It's obvious that my geometry is better than yours - just check the results on the golf course

[louis]

In a nut shell.

You are correct. Auto Roof Planes don't always work.

But in this case the problem was pretty simple. Either the pitch was wrong or the distance from the Garage Wall to the 2nd Floor Wall was wrong or the height from the Garage Plate to the Second Floor Plate was wrong.

It was simple geometry and something had to be adjusted. Doing it manually simply made the same adjustment. In this case making the adjustment first and then using Auto Roof Planes worked just as it should.

[perryh]

I guess my first fix was the correct one, don't know why, just fixed it.

[ebdesign]

As others have said, it's a basic geometry problem. But, what the heck, it was interesting.
The 2nd flr wall on the right is set back 9'-3" from the 1st flr garage wall on the left. Given equal roof properties & a 9/12 slope, the total rise is 110.25". That means that the absolute ceiling/plate hgts of those two walls/rooms need to have a difference of 110.25" (& roof baselines- assuming the base lines are over the wall main layer) The 2nd flr room had an assigned plate hgt (default) that was 5/8" too low. That is why Chief was generating two different roof planes w/ a small hip roof section coming up from the right side gable wall. Chief was just building what it was told to build given the room/wall properties. When the default ceiling/plate hgt for flr2 was raised 5/8", auto roofs worked perfectly. If raising the 2nd floor ceiling plate hgt is not gonna happen, then the difference would have to be made up w/ the rafter heel cut over one of the two walls......or one of the walls have to move (probably the garage wall- as Joe said).

There were plenty of "traps" in this plan that had to be dealt w/ before I got comfortable; the dimensional properties of the walls, auto & manual dimension locate properties. I turned on the tilde to see any dimensions that were not exactly what they said. The 2nd flr main front wall (in front of entertainment room) was not exactly co-linear w/ the short wall on the other end of the gable. The rear wall is 3 different walls which needed to be made co-linear. All this to be sure that the dimensions were locating what was assumed.
Fun little exercise.
Plan attached.
Jim

[Joe Carrick]

FWIW, if you simply change the roof pitch to 8-15/16" per foot it will work perfectly with your original plan without changing any plate heights or moving any walls.

I did not find any misalignment of the 2nd floor walls. I know there was a lot of discussion about this but I didn't see it in the plan when I opened it in X5. One way to check that is to open the Garage dbx and uncheck "Roof over this Room". Then rebuild the Roof Planes and look at the 2nd Floor Roof. It's perfect.

[dshall]

All I want to know is what mjrs thinks about this mess he started.

[mjrsr0403]

Thanks for all the discussion. There are a couple of good approaches here for solving my problem. I'm new at CA and predicting how it react to changes can be a crap shoot .... at least for me.

I figured that there might be a wall length or alignment issue that caused two roof planes to form rather than one, but I was not able to identify where the problem was. I even redrew the second floor as a simple rectangle to make sure the corners were square and the opposite lengths equal, and then built off of it. Maybe some of the snapping that went on as the other segments were added messed things up. The garage wall position seems to have been an issue, too.

The best solution would probably be to better learn to manually draw roof planes. I'm workin' on it.