To add a structural foundation in Revit, you typically navigate to the Structure tab and select the appropriate foundation tool, such as Wall, Isolated, or Slab, then define its properties and placement.
Understanding Structural Foundations in Revit
Structural foundations are crucial elements in any building design, transferring loads from the superstructure to the supporting soil. Revit provides dedicated tools within the Structure tab to model various types of foundations, ensuring accurate representation and analysis.
Step-by-Step Guide to Adding Structural Foundations
Adding foundations in Revit involves selecting the correct tool and defining its parameters. Here's how to create common foundation types:
1. Adding Wall Foundations (Strip Footings)
Wall foundations, or strip footings, run continuously beneath load-bearing walls.
- Navigate to the Structure Tab: In the Revit ribbon, click on the Structure tab.
- Select the Foundation Tool: In the Foundation panel, click on the Wall tool. This tool is specifically designed for creating foundations that follow the path of walls.
- Choose Foundation Type: From the Properties Palette, select the desired wall foundation type from the Type Selector dropdown. You can load additional types if needed (e.g., varying widths or depths).
- Modify Properties: Adjust instance properties such as:
- Depth: The offset from the wall base.
- Material: Concrete strength, etc.
- Structural Usage: If applicable.
- Placement Methods:
- Pick Walls: The easiest method is to simply click on the structural walls you want to apply the foundation to. Revit will automatically create a continuous footing beneath them.
- Sketch: For custom shapes or non-standard alignments, you can use sketching tools to draw the foundation's path.
2. Adding Isolated Foundations (Pad Footings)
Isolated foundations (pad footings) are typically placed under columns or concentrated loads.
- Access the Structure Tab: Go to the Structure tab in the ribbon.
- Select Isolated Foundation: In the Foundation panel, click on the Isolated tool.
- Choose Foundation Type: In the Properties Palette, select the appropriate isolated foundation family (e.g., rectangular footing, stepped footing). If the desired type isn't loaded, click "Load Family" and navigate to the Structural Foundations folder.
- Adjust Properties: Modify instance properties like:
- Dimensions: Length, width, thickness.
- Elevation: The offset from the current level.
- Material: Concrete type.
- Placement Methods:
- At Columns: Click the "At Columns" button in the ribbon. Then, select the structural columns you wish to place footings under. Revit will automatically center the footing beneath each selected column.
- Manual Placement: Click directly in the drawing area to place individual isolated footings at specific points.
3. Adding Slab Foundations (Mat/Raft Foundations)
Slab foundations, also known as mat or raft foundations, are large, continuous concrete slabs that support multiple columns and walls, distributing loads over a large area.
- Go to the Structure Tab: Navigate to the Structure tab.
- Select Slab Foundation: In the Foundation panel, click on the Slab tool.
- Choose Slab Type: From the Properties Palette, select the desired structural floor slab type. Ensure it's designated as a structural foundation.
- Define Slab Boundary: Use the drawing tools (e.g., Line, Rectangle, Pick Walls) to sketch the perimeter of your slab foundation in a plan view.
- Adjust Properties: Set parameters such as:
- Thickness: The depth of the slab.
- Offset from Level: Its elevation relative to the current level.
- Material: Concrete grade.
- Finish Sketch: Click the green checkmark (Finish Edit Mode) in the ribbon to create the slab.
Modifying and Adjusting Foundations
After placing foundations, you can easily modify them:
- Select and Edit Properties: Click on any foundation element to select it. Its properties will appear in the Properties Palette, allowing you to change dimensions, materials, and other parameters.
- Edit Boundary (Slabs): For slab foundations, select the slab and click "Edit Boundary" in the ribbon to modify its shape.
- Move, Copy, Rotate: Use standard Revit modify tools to adjust foundation placement as needed.
- Align and Constrain: Use alignment tools and constraints to precisely position foundations relative to other structural elements.
Best Practices and Practical Insights
- Always Use Structural Elements: Ensure you are using structural wall types and structural column types before adding foundations, especially when using the "Pick Walls" or "At Columns" placement methods.
- Work in Appropriate Views: While you can place foundations in 3D views, it's often more precise to work in relevant plan views (e.g., Foundation Plan) or section views.
- Review in 3D: Regularly check your foundation model in a 3D view to ensure correct placement and alignment with the rest of the structure.
- Load Families: Revit comes with a library of common foundation families. If you need a specific type not available, you can load it from the Revit content library or create a custom family.
- Foundation Depth: Pay close attention to the depth of your foundations, which is critical for structural integrity and should be coordinated with site topography and geotechnical reports.
Summary of Foundation Types in Revit
| Foundation Type | Description | Common Use Cases |
|---|---|---|
| Wall | Continuous footings placed directly beneath load-bearing walls. | Supporting perimeter and interior bearing walls. |
| Isolated | Individual pad footings designed to support columns or concentrated loads. | Under columns, piers, or heavy equipment. |
| Slab | A large, continuous concrete slab distributing loads over a wide area (mat/raft). | Basement slabs, areas with poor soil conditions. |
For more detailed information on structural elements in Revit, consult the official Autodesk Revit Help documentation.
