Revit 2019 Tutorial Part 2 - Creating Roof Bracing Systems
In Part 2 we will focus on roof bracing systems in Revit 2019
Roof bracing is often a little more complex than vertical bracing due to compound angles and complex connection configurations. Revit 2019 has some good tools to make the placement of roof bracing easier. We will also cover some tips and tricks for the representation of bracing in plan.
Part 1 of the tutorial highligthed that you should always use the dedicated brace tool over the beam command, as illustrated below.
Adding the roof bracing in 3D view makes things easier - just ensure you have the 3D snapping option checked on the options bar as shown below.
You can then roughly sketch your bracing configuration by snapping to the top of each rafter as shown below. Don’t worry about getting the exact position, this will be set in a later step. It's important to not snap to the column.
The bracing will automatically be placed on the centre line of the rafter, but the analytical model will automatically adjust to the top of steel.
The option of setting the location via a ratio or a distance along the beam is enabled when a brace is selected. The example below shows the start of the brace set 300mm from the column and the end of the brace set to 5,000mm. The plan shows the position of the brace.
Another method of placing the bracing is to use a ratio. The ratio at the start of the beam is 0 and the end of the beam is 1. In the example below a brace is placed 30mm from the start of the first rafter and then at a ratio of 0.25 (25%) along the second rafter. This value will remain parametric if the length of the rafter changes.
Plan Representation of Bracing
In part 1 of the tutorial you will have seen that plan bracing is represented in a course level of detail with an offset dashed line. While perfect for vertical bracing, this is not suited to roof bracing. In the image below, you can see the offset showing in the plan.
This is due to the plan representation showing a parallel line and offset. However, we will use the kicker brace symbol to represent the bracing in plan.
To set the bracing to kicker bracing, in the Properties Palette, set the structural Usage to Kicker Bracing as shown below.
In addition, you can edit the line pattern and the symbol for kicker bracing.
In the example shown below I simply edited the line pattern in the object styles for kicker bracing and deleted the X in the M_Connection-Brace-Kicker.rfa.
Adding Structural Connections in Revit 2019
You can of course add some basic connections in Revit 2019, but you must make sure that you create the bracing first and then add the relevant connections. If you add connections before the steel model is complete you will not be able to 3D snap to the rafter.
The Double tube bracing connection dialog box is shown in the screen shot below. The 3D representation of the connection is almost identical to the advance steel connection. If you require fabrication documents, accurate cutting lists, constructability verification and CNC code then Advance Steel can be used.
Advance Steel can create full fabrication documents and details. The image below shows the same frame in Advance Steel. This has been transferred using the Advance Steel extension which will keep both models synchronised.
Assembly drawings are automatically created for the rafters and haunches, as illustrated below.
You can find a list of plates and surface areas for galvanising below:
Finally the CNC data is generated for the automated drilling and cutting of each item in the model.
This is just one area you will learn more about by attending one of our Excitech’s Revit Training courses.
This article was originally posted on the Revit Structures Blog page.