Variable Thickness for Roof and Floor

The variable layer thickness parameter of roofs and floors affects the shape editing tools in the following ways:

·     When there is no variable thickness layer, the whole roof or floor slopes and maintains constant thickness between parallel top and bottom faces.

·     When there is a variable thickness layer, the top face of the roof or floor slopes, and the bottom stays in a horizontal plane, creating a variable thickness floor.

There is a Thickness property for structural floors. If the structural floor has a structural floor shape edit, and if the structural floor type contains a variable layer, then this parameter can be used to set the structural floor to a uniform thickness by entering a desired value.

To modify the variable thickness layer of a floor or roof

1. Select the floor or roof.
2. On the Properties palette, click Edit Type.
3. In the value box of the Structure property, click Edit.
4. In the Edit Assembly dialog, specify the material for layers and the thickness of those layers. The variable thickness parameter column will contain empty check boxes next to layers where variable thickness can be enabled.
5. Next to the desired layer of the roof or floor in the assembly, select the variable check box
6. Click OK until all of the dialogs are closed.
7. Click Modify | <element> tab Shape Editing panel Modify Sub Elements and make the desired changes to the roof or floor.

This works great when you are doing a flat roof with sloped rigid insulation.

The other method to create slope on a flat roof (and I've done it this way when building a construction model) is to create your main roof sloped as per the structural design and then create backslope using a new roof style that is just rigid and roof membrane and modify the points to create your slope.

With this method you can to a accurate take off of the sloped rigid that will be required......