Roof Planes


CompuDesign
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I'm trying to let auto roof build bumpouts that are 1' higher than the main structure. To let the hip continue over the lower roof and plane out, i've built temporary walls to create the higher plates. I know i can do this manually but with several bumpouts on this project, it would be nice not to have to manually build with each adjustment.

 

With plate heights all the same, the roof builds fine. When the bumpout is raised, an extra hip and ridge is created and the main ridge line moves off center. This is the case with all the bumpouts on this and the last project.

 

Any suggestions?

 

X13, RXT3080

CompuDesign

9' and 9' ceiling plan.jpg

9' and 10' ceiling plan.jpg

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As Eric mentioned a plan would be handy otherwise we are playing 20 questions.....

 

1.) make sure all Roof plane pitches are identical

2.) makes sure the Roof plane Baselines are where they should be ...ie over the main layer of their respective Wall.

 

M.

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 This project is quite large and reproducing small portions corrects the issue as you've shown. Althought the pitches are correct and base line is positioned properly, this roof does intersect other roof planes of different pitches and i'm getting the "roof structure does not touch top of plate" message. I'll look into this further and see if i can reproduce it on a smaller scale.

Thank you for your help!

 

CompuDesign

x13 RXT 3080

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I agree and saw the same. Those are temporary invisable walls so I tried interior walls and reversed them and still same results. I'm working on a simpler (smaller) version so i can upload it if nessesary.

 

Unfortunately this is a rework of an existing plan so no telling what may have been moved but i still think it could be related to pitch changes at the rear and the auto roof trying to level out the fascias but just guessing. There are some walls with the baseline off and manually adjusitng these reverts to original postion when auto rebuilt. I'm checking roof planes to see if I've locked something that's forcing the rebuild incorrectly. Everything works fine with front bump-out plate height the same as main body but stepping up might be giving the fascia a place to break and both sides are adjusting differently. Pure guess so still working on it because this is the 3rd house with this issue.

 

Thanks for reviewing!

 

CompuDesign

x13 RXT 3080

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2 minutes ago, CompuDesign said:

PS, all three houses have pitch changes at hips. Never have this problem on single pitch roof projects.

Different pitches will not line up in the 'center' of a room and will be offset as your pic shows. It is expected behavior and Chief is most likely building the roofs correctly but without a plan we might review it's just guess work.

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All the roof pitches in the problem area are 6/12. The program is moving the baseline in which is off setting the ridge. I experimented with changing the rear 5/12 pitch to 6/12 does correct the problem but i do need the pitch change for second story egress windows in this instance.

 

Attached is an overview of the first floor with the 5/12 pitched roof area hatched and all the rest is 6/12. In this view I've changed the 5/12 to 6/12 and all the problem areas have corrected themselves. Can you think of another setting or lock i can put on the roof/wall to avoid this? I can build the roof manually (and adjust overhangs accordingly) and it's fine but hoping there is a way to auto-build since this is, unfortunately, a common scenario for us.

 

Also attached are two screen shots of the settings auto-build has for the problem area and offset ridge.

 

Gettting closer so thanks again.

 

CompuDesign

x13 RXT 3080

 

2021-09-17 (2).png

2021-09-17.png

2021-09-17 (1).png

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29 minutes ago, solver said:

 

...don't know why anyone spends time guessing.

Dunno know either but kinda fun. The 2 baselines along the two 6' - 4" walls are different -  they don't line up. I think that's the problem you are describing? And the top of ridges are off by almost 5 ft? I'm out and best of luck until we can see the plan.

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Attached is the base plan for roof build problem solve.

 

Recap:

  • Trying to us auto-build roof for plans with multiple pitches.
  • This plan is 6/12 with noted rear porch pitches at 5/12 for second story window clearance.
  • This configuration creates roof problems as noted on the two front bumpouts with raised plates.
  • Changing the rear 5/12 to 6/12 corrects the problem but doesn't solve the issue. Same issue on other plans as well.

I'm hoping there is some way to lock a setting so that the overhang depth is adjusted vs the base line moving in auto build so as not to manual build in this situation.

 

Thank you

Jones Roof Test.plan

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interesting that you would have to specify that(Check Same Roof Height at Exterior Walls), as that setting forces the eave width to  vary, if the pitch is the same, as far as I can tell at least by reading of the help:

 

"Check Same Roof Height at Exterior Walls to keep bearing walls the same height and change horizontal roof overhang distances as needed so that eaves meet correctly. When checked, this option ignores any overhang values you may have entered in the Wall Specification dialog. See Aligning Eaves.

Uncheck this option to raise or lower some roof planes relative to the wall’s top plate, allowing all horizontal overhangs to be the same unless a non-default value has been entered in the Wall Specification dialog"

 

I use the "Same height eaves" check box as it defaults "on" for me, and it also fixes the OP's problem.

 

Without either of these settings, what I notices is the one roof plane is locked to top plate and the other locked to baseline. When you have neither of the options checked, the baseline for the right roof plane "moves" (As compared to with them checked) from the outside of the wall to the inside. which makes me think it has something to do with the rest of the "L" structure. If I delete the rest of the L structure on the right, then the roof planes draw correctly with neither of those two settings checked. It's like CA is bumping the baseline over due to the abutting structure. It would be interesting to hear what CA thinks about this behaviour.

 

I did check the eave distances for all three scenarios, and they are all at 1'4. so it looks like it is only the baseline "moving" which causes this behaviour.

 

I've seen similar  behaviour before as well where the auto created roof planes seem to have different settings, after they are created wrt top plate/baseline differences. Good to know I am not the only one, and more importantly, what might be contributing to it, and potential methods to correct them

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