Change in Roof Pitch Along a Single Wall

[davidstvz]

I'm using HD Pro 2020. I tried to ask about this in Home Talk Q&A, but no one there answered. I'm assuming the auto-roof system works the same in Chief, so this should still be a relevant topic here.

 

I need to do a hip roof with pitch changes along a single exterior wall (common on real-world roofs).  I've attached an example image of what it should look like.  The ceilings are the same (9') throughout.  The low roof is 9 over 12 and the higher part has a 9 over 12 skirt around the edges to match, then changes to 16 over 12 starting 0.5" from the baseline.  As you can see, the 16 over 12 section has 4 roof planes, but the 9 over 12 section only has 3 planes with the side planes intersecting the higher roof section.

 

I've tried making this in several ways:

 

1) If you try to simply split the long exterior walls in half and give different pitch directives, the auto roof chooses one of the two pitches and ignores the other.  This almost feels like a bug as it's not the behavior you would expect.  I realize that this kind of roof creates a roof plane over the interior, but the auto roof could at least guess at what the pitch should be or use the default.

 

2) If you make two roof groups using a room divider, you end up with two entirely separate roofs (8 planes with two points instead of the 7 planes you see pictured). In this case the system sets the internal pitches to the roof default, but won't join hip roofs.

 

3) If you make two roof groups as above and make roof baseline polylines, you can change the interior pitches. Set the low one to "against wall" and the high section to 9/12 and 16/12 to match the exterior walls, and manually intersect them by moving the "against wall" baseline into the higher roof.  However, then the lower roof extends into the attic of the higher roof which isn't ideal since I'd like to visualize the attic space properly.

 

4) Finally, if you use one roof group and manually create two separate baseline polylines via copy/paste.  You can set the separate roof directives as above, but if the outer lines are flush, then just as in (1) it chooses one of two baselines along the edge and ignores the other.  If you separate the baseline polylines by a fraction of an inch along the exterior wall it creates separate planes as intended (this is how I made the pictures and it almost works), but it creates a discontinuity along the eaves that you can see in the 3D view (pictured) and it causes the shingles over the 16/12 hip to extend all the way down whereas they should stop around 0.5" from the baseline.

 

Is there any way to do this correctly without resorting to a completely manual roof?

 

As a separate issue/observation, it seems that roof baseline polylines inherits the roof group from the room it sits on top of when created, but there is no way to see or change the roof group of a roof baseline polyline in the Object Specification dialog (opened with Ctrl+E) of HD Pro 2020.  Maybe you can see it in Chief Architect products.

 

[DavidJPotter]

I never bothered to learn or use the "Roof Poly lines" tool, they added it around 10 years ago and by that time I was proficient using Wall specification Dialog - Roof Tab settings and manual roof creation and editing. I did not see any advantage to that tool when it was first released. That said, Chief and Pro generates by default hip roofs at a pitch set in the "Build Roof-pitch" input box and if you wish to diverge from that global setting you use the wall specification dialog - pitch input box to set a differing roof pitch. It seems quite straight forward to me. I have observed that new users who try to use the "Roof Poly lines" tool often complain of trouble from that use  and perhaps not fully understanding  roof tools and settings in the first place.

You mention "Roof Groups" several times and that is another concept that I have never found a use for. I create roofs where they are intended to exist, by presets or manually. I am sorry it this perhaps does not directly address your questions but in 24 years of use of this software I use and do what works for me and ignore the rest.

 

Your posted images did not help me fully understand your quandary, sorry. Can you find and post a clear image of what you are trying to emulate please?

 

DJP

[davidstvz]

DJP, I've asked a clear question and shown a clear example of what I want to achieve and outlined in detail 4 ways I've tried to achieve it.  You say it's easy and I clearly don't know what I'm doing, yet you don't actually address the question (how to create two different pitches along a single exterior wall) or show how to do it.  Can you do it without manual roof planes or can't you?  If you can, please explain or demonstrate how.

 

And if roof baseline polylines and roof groups are so useless, why did Chief create them?  Clearly they are there to bridge the gap between wall directives and a fully manual roof, and personally I find they do a good job except this one issue I can't seem to resolve.

[GeneDavis]

HD Pro has its own discussion forum.  This is the one for Chief Premier users, most of whom do not know how HD Pro works.

[davidstvz]

I know, but there are a lot of similarities between the programs right?  Chief Premier has roof baseline polylines and automatic roof generation just like HD Pro does.  The answer to the question might use features that are available in HD Pro, so it's worth a shot.

[Alaskan_Son]

Short answer...

 

I think it can probably be forced by jumping through a bunch of hoops, but I think this is one where manual roofs are the better option.

[DavidJPotter]

Is this what you are trying to do, take a look?

 

DJP

[davidstvz]

It’s close, but the roof baseline height does not change between the sections. The roofline, eaves and soffit are all seamless along the two sections where the pitch changes. The house I live in now has this design. It’s on the plan and you can see the change in pitch from 9/12 to 12/12 clearly from within the attic. Might be time for me to learn manual roof editing.

[DavidJPotter]

Your posted image shows "roof poly lines" all set at a pitch of 9/12. If that were true you would not get the roof geometry that your image shows, what I mean be that is if all pitches are set to 9/12 you would end up with a perfectly symmetric roof system and that is not what your posted images show. No one who has looked at your posts have been able to "solve" your problem and answer your questions to date either here or at Home Talk because you have not, to date made your question clear and you have been unwilling to help those who would help you understand what is what (no matter what you think you have communicated to date has made your situation clear).

 

In order to answer a question, it must first be offered so it can be clearly understood by those who would help.

 

DJP

[Chopsaw]

David,  I believe the question has been stated clear enough that it could be answered if the software was capable of doing what he needs automatically.  There are a couple of small details that could be clarified but would not affect the requested answer.   I am not sure I know how to do it automatically but you have a lot more experience with Home Designer than I do.

 

Chief does not show the "Upper Pitch" in the auto Roof Baseline Polyline label.  And yes maybe they should.

 

I believe this is what he is after:  Except that there was a later reference to a 12/12 section that may have been in error as it was originally described as 16/12.

 

                     

 

 

[davidstvz]

@Chopsaw, your elevation does show exactly what I'm after.  I didn't realize there would be so much confusion about this or I would have posted the elevations for the house I live in.  I'll post them now.  The house I live in is 9/12 and 12/12, but I made the example 9/12 and 16/12 just so the change in pitch would be very obvious.  And you're correct, the roof baseline polylines don't show the upper pitch on the label.

 

I can see why DJP might assume the roof changed height as that is often how this situation is handled. I have no idea how rare this technique is, but I can at least say that the architect for my new house is also using it in one spot.  Maybe it's more common in south Louisiana.

 

If I have to do this with a manual roof, then it's probably premature for me to ask questions about how you did that.  I need to go through manual roof tutorials and get some practice first.  I know the very basics of drawing new planes or modifying existing ones, but whenever I try to do anything complex I end up with seams that won't meet up.

 

Note about the attached elevations: I doubt anyone is looking at them this hard, but there is a section of house visible on the rear elevation which is not actually present and doesn't appear in the front or right-side elevations. I guess they shrunk an existing plan and forgot to remove that from the rear elevation.

 

If anyone wants a plan file for the house in the elevations, it's attached to this post:

 

https://hometalk.chiefarchitect.com/topic/6331-using-roof-baseline-polylines/?do=findComment&comment=32722