roof pitch help

[stl4310]

I'm having problems pitching the insulation on my roof deck and need some help.

Problem:
I have a roof deck with a constant slope of 1/2": 1' from front to back. On top of this I want to put tapered insulation which will need to bend and weave around several roof skylights.

What I've tried so far:
First, I tried to modify the sub-elements of my sloping roof deck. Apparently you can only modify the sub-element if the roof is flat, as I was only able to edit the profile, not the sub-elements.

Then I created a separate roof, independent from my structural deck, just for my tapered insulation and waterproofing. It was a flat roof and I modified the sub-elements to achieve my desired insulation pitches. At first this seemed to work. Then I realized that the problem with this method is that the bottom of the insulation is not parallel to my sloping roof deck, as it follows the pitch of sub-element modification instead, leaving gaps between it and my single-pitched deck.

Finally, I thought maybe I could create a flat roof with ~2' of insulation, changing the insulation thickness to variable. That way, the 18" total drop from front to back of my roof would still give me enough room for all of my sub-element modification. Problem is that I still have a flat roof, when I need a pitched structure.

Any way to get the effect I desire that I haven't thought of?

[cliff collins]

Try using a Compound Roof, with the decking and insulation, then use a Slope Arrow to give the whole roof your desired pitch.

You specify the heights at the tail and head of the arrow when in sketch mode. Works pretty well. If you still need "crickets" around protrusions, etc.
you can build you main roof "flat" first, add the individual "crickets" on top, by editing points, then "tilt" the main roof by slope arrow method, or aligning to an angled
reference plane, etc. i.e. there are several "tricks" to get what you need.

[stl4310]

i cannot get my flat roof to align to an angled reference plane...it says "can't change roof plane of sketch"

[dzatto]

Try naming the sloped reference plane. Then, select the roof, edit work plane, and choose the newly named reference plane. Does that work?

I don't think you can do it using the align tool.

[stl4310]

I have named it, but when I select the roof it won't let me select the work plane that I just created.

[dzatto]

Yeah, same thing is happening here. Cliff, help please......

[cliff collins]

Try going into sketch mode, cut the sketch lines to clipbd, then set current workplane to the named ref. plane, create a new roof by footprint, paste in sketch lines.

Does it work?

[stl4310]

When I try to paste the lines it says: "the work plane of this view cannot be used for this operation. This operation should be performed in another view or the work plane of this view should be set to a Level by using the Work Plane command."

[mdradvies]

I'm not quite following the OP. Could you post some pictures? Or a part of the file?

[Ian.Kidston]

Last time I had something similar to do, having never found a successful way of using roofs or floors to do tapered insulation, I created a simple roof based family.
I have attached the very quick and basic family I created at the time for the particular roof I was designing. It might be useful or be able to be modified to suit you needs.