understanding revit roofs: the forgotten optionsunderstanding revit roofs: the forgotten options 3...

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TECHNICAL WHITEPAPER

Understanding Revit Roofs: The Forgotten Options

I had a client recently who does residential roof framing and wanted to know Revit’s capabilities to create specific overhangs and precise details with Roofs. While Revit does have the features they needed, it was just a matter of demonstrating where the options lie, and how to use them. This paper addresses many of those hidden options inside roofs.

Forgotten Option 1: Pick Walls vs. Every Other Draw ToolWhen using Roof by Footprint there are many draw tools available. However, only using the Pick Walls tool actually HOSTS the sketch line to the wall. Although all pink sketch lines look similar, they produce very different results if you use Pick Wall.

Table of Contents

■ Forgotten Option 1: Pick Walls vs. Every Other Draw Tool

■ Forgotten Option 2: Truss or Rafter

■ Forgotten Option 3: Rafter Cut

■ Forgotten Option 4: Cutoff Level

■ Forgotten Option 5: Slope Arrow for Link Dormers

■ Forgotten Option 6: Capping the Soffit Ends

■ About the Author: Heather Alley, R.A.

mailto:[email protected]

http://www.imaginit.com

Understanding Revit Roofs: The Forgotten Options 2


Pick Walls, with a 2’-0” Overhang, Extend to Wall core checked, produces this result:

In contrast, using any other draw tool will produce a different result. In this example, we used Pick Lines, with a 2’-0” Offset. There is no option to host this line to the Wall’s core, so it offset’s from the face of the wall.



Forgotten Option 2: Truss or RafterNow that we have used our Pick Walls tool with a 2’-0” Overhang, let’s explore it’s bearing point. Another option occurring in the Roof Properties is whether the roof is set to be a truss or rafter.



Forgotten Option 3: Rafter CutAdditional options in Revit have to do with the termination of the rafters at the eaves. Revit gives us three options. The default is Plumb Cut, as we have seen in the previous images. Two additional options, Two Cut-Plumb and Two Cut Square require us to also input the fascia depth in order for them to work properly.



Forgotten Option 4: Cutoff LevelAfter selecting a roof you will see “Cutoff Level” in the properties dialog box. It essentially draws a big hole in the roof. This can be used to create Mansard or Gambrel roofs, or could be used to create two roofs with varying thicknesses. In the example below, I drew two separate roofs.

Step One: The first roof I drew had a core thickness of 5 1/2” with a cutoff level of Bearing Height, and I made some adjustments for Cutoff Offset and Base Offset from level (-0’-2” for both). I used Pick Walls, with a 2’-0” Overhang, and Extend into Walls (to Core) checked on. Finish the roof sketch.



Step Two: I then drew a second roof with a 7 1/2” thickness on the inside of the first by using Pick Walls with Extend into Wall (to Core) checked on, and no overhang.

Step Three: My final step is to clean up the intersections. Select the Wall and use the Attach Top/Base button to attach it to the underside of ONLY the 5 1/2” roof. Then, from the Modify tab on your ribbon, use the Join Geometry command, and select the 7 1/2” roof and the wall. It will join in the wrong order, and you will need to use the drop down menu next to Join to Switch the join order.

Your final result:



Forgotten Option 5: Slope Arrow for Link DormersWhile many people are aware of the slope arrow and how to use it, there is a little known workflow for making link dormers, or dormers along the eave line.

First, I need to use Split Element to divide one eave line into 4 separate pieces. Only one of the pieces is selected in the image below.

Second, I have drawn two slope arrows along the eave of the roof, on top of the middle two sketch lines, snapping to their end points. I have selected one of the slope arrows below.

The resulting link dormer:



Forgotten Option 6: Capping the Soffit EndsSo you want this detail on your roof:

However, Revit only gives you this as its detail: In this view, I have added a Roof: Fascia Sweep to both the eave and the rake. I also have created a Roof: Soffit. I still need to create a soffit cap.

First, I want to make sure that the end of my soffit is in line with the edge of the roof. In the Soffit sketch, it is important that it aligns with the edge of my roof.



Next, I will use the Roof: Fascia tool to sweep along Eave and the Rake, which still leaves me with an open end.

In order to close off the end of the soffit, I will create a new fascia sweep, but I will host it to the SOFFIT, not to the Roof Eave or Rake. I will then adjust its Vertical Offset dimension in the properties menu.

The final step is to use the Join command on the Modify Tab to join the two fascia boards together. The final result:

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Understanding Revit Roofs: The Forgotten Options

About the Author: Heather Alley, R.A.Since 2003, Heather has worked in the field of architecture where she found that her love of technology matched her interest in design and began working with BIM software early on in her career.

At IMAGINiT, Heather puts her love of technology to work for our clients. Being able to give students that ‘A-HA!’ moment is a great feeling and instructing power users provides an outlet to learn more and stay ahead of the curve. Clients look to Heather not only for her expertise with Revit but also for her knowledge of how programs can work in real-life situations.

Alternate Option: As another option to hosting the extra Fascia cap to the SOFFIT, Revit also allows you to host the Roof: Fascia to a model line. I drew a model line along the workplane of the rake, and along its return back to the wall. I can then host the Fascia to the model lines. Use Join Geometry on your Modify tab as the final step to remove the black lines.

understanding revit roofs: the forgotten optionsunderstanding revit roofs: the forgotten options 3...

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