Message: The Main Layers for this wall type are unusually thin.

Reference Number: KB-00174
Last Modified: July 20, 2021

The information in this article applies to:

Chief Architect Premier or Chief Architect InteriorsVertical SeparatorHome Designer Professional or Home Designer Architectural


I received this warning message.

"The Main Layers for this wall type are unusually thin."

What does it mean and how can I correct my plan so I no longer receive this warning?


The reason this warning displayed is that you have set the Main Layer for the wall type to a thin surface layer.  Double check to make sure this is what you really intended to do.  If not, follow the instructions below to restore the Main Layer back to the Framing.

In most circumstances, the Main Layer should be specified as the structural layer of the wall, particularly when the wall is a framed type.

The Main Layer determines many things, including:

  • Floor and ceiling platforms and automatically built foundation walls normally build to the outer edge of the Main Layer.

  • At intersections, walls join at the interior surfaces of their Main Layers.

  • Exterior walls on different floors are aligned by the exterior edges of their Main Layers.

  • Roof baselines are placed at the outer edge of the Main Layer when roofs are automatically generated.

  • Roof base lines and gable/roof lines that are manually drawn snap to the edge of this layer.

  • When wall framing is generated, stud depth is based on the thickness of each wall’s Main Layer.

  • By default, walls resize about the exterior surface of their Main Layer when their wall type or Wall Type Definition is changed.

  • By default, Object Snaps locate the exterior surface of a wall’s Main Layer.

Wall framing will only generate in a wall when a Framing material such as Fir Stud 16” OC or Metal Stud 24” OC is specified for its framing layer. 

All of this information is reliant on the Main Layer, so creating your wall type definitions accurately and specifying the Main Layer correctly before creating your floor plan is very important.

To set the Main Layer

  1. Select Build> Wall> Define Wall Types  to display the Wall Type Definitions dialog.

  2. From the drop-down menu, select the Wall Type that you just modified which generated this warning.

  3. Using the Move Up and Move Down buttons on the right side of the dialog, restore the Main Layer back to the Framing (often the thickest) wall layer.

    In Chief Architect X6 and prior, place a checkmark beside the layer that you want to be the Main Layer. 

  4. Click OK to close the dialog and apply the changes.