How To Attach Window Trim Inside Rounded Corners?

This tutorial demonstrates how to trim rounded window corners in a home, including replacing the window ledge, painting and fitting the inside trim, attaching the outside trim, and ensuring a clear reveals between the inside and outer trim. The process begins with deconstruction, where existing window trim is removed. Then, the window ledge is replaced, and the inside trim is painted and fitted. The outside trim is then attached.

The tutorial also covers installing a wide trim around a door and window, complete with mitered corners. It also demonstrates how to install a built-up baseboard made from a solid composite material. For the kitchen, a simple square frame using craftsman molding (MDF) is used, and the corners are trimmed using a butted corner casing.

To change out boring rounded window corners for a timeless craftsman style, the tutorial explains the steps from selecting materials to the final installation. The simplest window casing consists of flat stock trim with butted corners, which eliminates the dreaded “opened” miter joints.

To install the inside trim, cut boards to size and miter the corners at 45 degrees. Use 2 inch brad nails to secure the trim. The tutorial concludes by demonstrating how to easily add trim and baseboards to interior windows with rounded or bullnose corners.