How do you join split walls in Revit?

To join split walls in Revit, you employ different techniques based on how the walls are split. This might involve horizontally stacked walls, walls split along their length, or walls that need to clean up at intersections.

Understanding Different "Split" Scenarios

Identifying the nature of the "split" is the first step:

Horizontally Split Walls: These are typically two distinct wall instances stacked one above the other, but intended to appear as a single continuous vertical wall. This is common when walls span multiple levels or have varied properties at different heights.
Longitudinally Split Walls: A single wall element that has been divided into multiple segments along its horizontal length (e.g., using the "Split Element" tool). You might want to merge these back into one continuous wall.
Intersecting/Adjacent Walls: Walls that meet at a corner or intersect, where their geometry isn't cleaning up correctly or they aren't forming a cohesive joint.

Method 1: Joining Horizontally Split Walls (Vertical Alignment)

This method is crucial for walls that are stacked vertically but need to appear connected and aligned.

Scenario: You have a wall on one level and another directly above it, and you need their edges to align perfectly for visual continuity or to manage their shared boundaries.
Steps to Merge Horizontally Split Walls:
1. Create a Section View: To accurately manage and adjust walls stacked above each other, create a section view that cuts through both the upper and lower wall segments. Ensure the section view's range includes both elements.
2. Navigate to the Section View: Open this new section view from the Project Browser.
3. Adjust Wall Edges: In the section view, select the upper wall segment. You will see blue control grips at its top and bottom edges.
4. Drag and Connect: Pick the bottom control grip of the upper wall and drag it downwards until it snaps precisely to the top edge of the lower wall. This action extends or shortens the upper wall to meet the lower wall, visually merging them and facilitating better geometric interaction.
5. Alternative (Bottom-Up): You can also select the lower wall and drag its top control grip upwards to meet the bottom edge of the upper wall, achieving the same alignment. The objective is to ensure their boundaries are coincident.
Practical Insight: While this method ensures precise visual alignment and connection, it typically does not merge them into a single Revit element. If you require a single wall instance spanning multiple levels, it's often more effective to model one wall with appropriate base and top constraints, potentially utilizing the "Attach Top/Base" tool.

Method 2: Joining Walls Split Along Their Length or at Intersections

For walls that are split into segments horizontally or need to properly connect at corners, Revit provides dedicated modification tools.

1. Using the "Join Geometry" Tool

The "Join Geometry" tool is essential for ensuring that intersecting or adjacent elements clean up correctly and share common geometry.

When to Use:
- To clean up messy intersections where walls meet or cross.
- To ensure materials blend correctly at junctions, providing a more realistic visual representation.
- To improve accuracy in material take-offs by preventing double-counting of shared volumes.
Steps:
1. Go to the Modify tab > Geometry panel.
2. Click the Join Geometry tool.
3. Select the first wall you want to join.
4. Select the second wall you want to join.
5. Revit will then merge their geometry, cleaning up the intersection. The order of selection can sometimes influence the result; use "Switch Join Order" if adjustments are needed.

2. Using "Trim/Extend" Tools

These tools are highly efficient for precisely adjusting wall endpoints to meet other elements.

Trim/Extend to Corner:
- When to Use: To quickly form perfect mitered or butted corners between two intersecting walls.
- Steps:
  1. Go to the Modify tab > Modify panel.
  2. Click Trim/Extend to Corner (the icon showing two lines forming a corner).
  3. Select the two walls you wish to join at a corner. Revit will automatically trim or extend them to create a clean corner.
Trim/Extend Single Element:
- When to Use: To extend a wall to meet another element (like another wall, a line, or a grid) or to trim a wall back to a specified boundary.
- Steps:
  1. Go to the Modify tab > Modify panel.
  2. Click Trim/Extend Single Element (the icon showing a line extending to another).
  3. First, select the boundary element (the wall or line you want to extend/trim to).
  4. Then, select the wall you want to extend or trim.

3. Dragging Wall Endpoints

For walls that were split along their length (e.g., using the "Split Element" tool) but are intended to be a single, longer segment, simply dragging their endpoints can rejoin them.

When to Use: When you have two adjacent wall segments of the same type that were once continuous and you want to make them one element again.
Steps:
1. Select one of the wall segments.
2. Hover your cursor over its endpoint (the blue dot).
3. Click and drag the endpoint until it meets the endpoint of the adjacent wall segment. If they are of the same type and perfectly aligned, Revit will often merge them into a single continuous wall element automatically.

Practical Considerations and Troubleshooting

Consistent Wall Types: For walls to fully merge into a single element when dragging endpoints, or to clean up seamlessly with "Join Geometry," they should ideally be of the same wall type. Different wall types will often remain distinct, even if their geometry is joined.
Wall Joins Dialog: When walls meet, Revit automatically generates wall joins. You can control their appearance and behavior using the "Wall Joins" tool on the Modify tab. This allows you to select between miter, butt, or square-off joints, and to prevent or allow specific joins.
Revit Warnings: Always pay attention to warnings generated by Revit, such as "Walls overlap" or "Highlighting walls that overlap." These indicate potential geometric conflicts that require resolution for an accurate model.
Attaching Walls: For walls that extend up to meet roofs or floors, the "Attach Top/Base" tool is crucial. This ensures the wall's top or base conforms precisely to the shape of the attached element, which is a different operation from joining split walls but a vital part of comprehensive wall modeling.

Summary of Wall Joining Tools

Tool	Primary Use Case	Location	Notes
Section View & Drag	Merging horizontally stacked wall segments for vertical alignment.	(Modify Wall in Section)	Ensures precise visual connection and alignment of vertically separated walls.
Join Geometry	Cleaning up intersections between walls, or between walls and other elements.	Modify tab > Geometry	Essential for material continuity and accurate quantity take-offs.
Trim/Extend to Corner	Quickly creating perfect corner connections between two walls.	Modify tab > Modify	Ideal for L-shaped or T-shaped wall junctions.
Trim/Extend Single	Extending or trimming a wall to a specific boundary (another wall, line, grid).	Modify tab > Modify	Provides precise control over wall endpoints.
Drag Endpoints	Rejoining longitudinally split wall segments into a single continuous wall.	(Select Wall)	The most direct method for segments of the same wall type that were previously separated along their length.

By employing these specific tools and techniques, you can effectively manage and resolve various "split wall" scenarios in Revit, leading to a more accurate, clean, and well-coordinated architectural model.