how do i create an industrial flat roof

[learningbim]

looking to create a generic flat roof (in 2011 bim) with 1/4" slope to drains. girders and framing as well.

[bcd]

We have a very illustrious poster here who has grappled with this very issue. Please stand by.

[bcd]

Try this it's a little tedious but should work:

Draw your building perimeter walls.

Select all.

AEC Create Roof - set your bearing inset to 0 and your slope to positive 1/4"

Modify> Ungroup to break into individual Roof Faces.

Edit Group (or Ungroup) to get to them.

One by one-

Select a roof face - a line with two handles and an arrow describing the up-direction defining the roof 'axis' appears. Drag its handles to the opposite ends to reverse the slope.

Next.

You can crop the excess roof face by drawing a polygon highlighting it and the roof face Modify>Clip Surface.

Then move the entire roof system to the correct z-value.

This doesn't resolve for sloped drains.

Edited January 3, 2011 by bcd

[RubenH]

You can use, directly, the roof face for the sloped drains. Use horizontal miter!

[Patrick Fritsch]

Bringing this one back from the dead.

So i'm noodleing with extrudes and tapering their tops to create a flat roof that slopes 1/3" per 1'-0" toward 2 central roof drains...The problem is the edge has to be all the same thickness but the 3d tools do not give any grips to modify the solid as if the were all Sketchup Sticky faces. The only way is to convert to 3D polygons and drag each grip to adjust....Need better 3D modeling tools for this.

At least with the 3D polygons I can texture each individual faces.

[mike m oz]

There are two ways to do it. For both you need to work out your valley lines and the outlet height relative to the edge height.

METHOD A:

- Create a full height extrude for the roof area being drained.

- Create a multiple extrude for the part to be removed.

- Use solid subtraction to remove that part from the whole.

METHOD B

- Model each of the individual slopes at the full height.

- draw a line from the drain point at right angles to the high edge.

- Use the Taper Face tool to change the top surface into a falling surface.

- Use solid Addition to create a single object from the multiple objects.

Yes you have to do the maths but the reality is you would probably need to do that anyway.

[Patrick Fritsch]

Thanks Mike, I figured out how to get it done with decking, insulation and tapered insulation as well. Math is not my problem, it just feels more laborsome to model that the other modelers I use. We need better 3d tools in my opinion.

[mike m oz]

One of the regulars has been asking for a flat roof tool for years. ie a tool that will draw roofs with a horizontal bottom surface and a top surface which has falls to a drainage point.

Petri cam up with a tool that worked but unfortunately it never made it to being a for sale tool.

[VincentCuclair]

I would personally do it like this:

1. Create a slab with the same profile as the whole roof and a thickness slightly less than the thinest part of the roof.

2. Create roof faces for the sloped parts with a thickness slightly more than the slope height difference.

3. Let all these parts overlap in such a way that the section (and other views) look like a solid (no gaps between the roof faces and slab).

This way you can use the slab and roof face properties eg texture mapping, roof lights, roof slope etc.

This only works if the max slope height difference isn't greater than the thinest part of the roof, in this case more separate slabs/roof faces are needed.

(You could add all these objects and make one solid addition of them once your done if you only want one object).

Edited September 12, 2014 by Vincent C