Add Character with a Box-Beam Ceiling
Hollow beams transform a room’s trim detail while making it easy to integrate lighting and run wiring.
Synopsis: Box-beam ceilings can add elegance to any room: round, triangle, square, or rectangle. By adding a soffit, you can normalize an oddly shaped room to accept this ceiling treatment. The hollow beams are great for installing lights and hiding wires or pipes in remodels. Veteran finish carpenter Chris Whalen shows how to assemble a simple box beam using quirk joints between the sides and bottom, and gives several options for intersecting the bottoms of the beams across the grid.
Box-beam ceilings are a great way to add personality, elegance, and character to an otherwise ordinary space. In a room with an oddly placed structural beam, box beams can make sense of the unbalanced ceiling. Furthermore, the hollow beams can house recessed lighting and provide a chase for wiring. Whether the beams are painted or stained, the layout principles are the same, and the joinery and design can be as simple or as elaborate as you want.
A recent restoration that my company undertook provided an excellent opportunity for a box-beam ceiling: a 1970s breezeway connecting a 19th-century Queen Anne Victorian to its detached garage. The box beams and custom wall paneling helped to convert this cold breezeway into an inviting entertainment room, a cozy place to enjoy the fireplace, the wet bar, and the entertainment center.
You don’t need a perfectly shaped room
Although square or rectangular rooms are the most likely candidates for box-beam ceilings, almost any room shape will work, even circular or triangular rooms. The key is to create a symmetrical layout. The breezeway is roughly rectangular, with a small bump-out in the ceiling on one end. We eliminated the bump-out by adding a soffit to one end of the room.
A typical box-beam installation usually includes some sort of perimeter band that the box beams butt into. Because banks of tall windows ran along the sidewalls, we chose to run the window head-casing assembly (which extended to the ceiling) continuously around the room, thus using it as the band. The head casing had a curved face, so the beam ends needed to be scribed and cut to fit tightly against the profile.
The grid created by the beams should be either rectangular or square. We designed a square grid that lined up with other details in the room. Along one wall is a fireplace with flanking bookcases. Dividing this space with two beams centered the fireplace nicely and visually separated the bookcases. Placement of the perpendicular beams was determined by the space between the first two; adjusting the soffits made the grid roughly square.
There are many ways to make a box beam
The size of the perimeter band determines the height of the box beams. We could have aligned the bottom of the beams with the bottom of the band, but because the ceilings in this breezeway are about a foot and a half lower than the 10-ft. ceilings in the Victorian house, we were nervous about making the room too short and top heavy. Instead, we chose 1x4s for the sides of the beams and used a 1×6 for the bottom.
There are several ways to assemble the box beam itself. Our design, which relies on rabbet joints and a simple cove molding, manages to convey Craftsman-style detail with simple joinery.
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