how to extreme

DIY Making a Fireplace Mantel

Construction How-To, Mantels. Trim, Molding, Related Products, Trim Carpentry February 16, 2011 Sonia


Article Written and Photographed by Larry Walton

 

This classic mantel features an arched frieze and can be built using basic carpentry skills. 

 

You have many options when it comes to fireplace design, like fuel types, locations, firebox liners, ventilation systems and masonry treatments. Mantels alone include a whole array of choices. A fireplace mantel can be natural wood or painted. It can include legs (pilasters) or may even incorporate a bookcase or other storage on each side.

Sketch out the plan for the mantel to get an idea of the proportions you want.

Sketch out the plan for the mantel to get an idea of the proportions you want.

Some mantels extend all the way to the ceiling and include alcoves for displaying art or housing video screens. Surface design options include appliqués, fluting or surface designs. Raised or recessed panels can also be incorporated into the design. Mantels can be as rustic as a log set in river rock or as refined as the most elegant piece of furniture.

Use a level to mark the vertical lines plumb and the horizontal line level.

Use a level to mark the vertical lines plumb and the horizontal line level.

Starting with the firebox. Measure and mark the width of the granite plus 3/4". Measure from both sides of the firebox as well as above the firebox.

Starting with the firebox. Measure and mark the width of the granite plus 3/4″. Measure from both sides of the firebox as well as above the firebox.

Plan the Design

Mantels are either built in place or built as a unit (on or off site) and installed. How you attack your mantel job depends on your starting point. If you are building a mantel on a new fireplace install, check with any other trades for the order in which to do the job. Some stone masons prefer to have the mantel in place before setting any surround materials while others would like to set the masonry first and then have the mantel built around it or installed over it. This doesn’t mean that the mason or stone setter should call the shots, but if they have a preference you might as well ask them before ignoring them.

Measure and cut backing for the legs. The legs should extend from the floor to the bottom of the mantel shelf.

Measure and cut backing for the legs. The legs should extend from the floor to the bottom of the mantel shelf.

No matter the design or sequence of the mantel install, it must be built and installed with strength in mind. While mantels are decorative in themselves, they also function as a display shelf for the most precious of family heirlooms, so we have to make sure they are sturdy and well anchored to the house.

Horizontal blocks can also serve as backing for the legs depending on framing location.

Horizontal blocks can also serve as backing for the legs depending on framing location.

If there is no wallboard up, you have an opportunity to add some framing to help anchor the mantel. Do so as long as it doesn’t violate the required clearances for combustible materials.

Rip the side wall pieces for the mantel legs. Cut the leg face pieces to length, and then rip the leg face pieces to width.

Rip the side wall pieces for the mantel legs. Cut the leg face pieces to length, and then rip the leg face pieces to width.

Besides being sturdy, the mantel shelf itself must be deep enough to accommodate the items you wish to display there. Also, determining the mantel size is the size of the room. If the room is large and has high ceilings, you can and should build a larger mantel. Intimate spaces, on the other hand, should not be overpowered by a bulky mantel.

Sand the saw marks off the edges of the leg face pieces. Use a router to ease the edges.

Sand the saw marks off the edges of the leg face pieces. Use a router to ease the edges.