A fireplace is a lovely centerpiece for any home. Unfortunately, many lack a mantel. The mantel extends the joy of your fireplace by creating a space to build and honor family memories, from hanging stockings to housing cherished family portraits. Fortunately, it’s easy to build a fireplace mantel of your own. With the right tools, it makes a great weekend project.
The length from start to finish will vary based on the stain you use. The building and hanging of the mantel itself will take 3 to 4 hours. Sometimes less for an experienced woodworker. The staining process can vary from 3 to 9 hours, depending on whether you use water-based or oil-based stain. If you choose to use a polyurethane sealer, you may add 24 to 48 hours and need to wait before you can use the surface of your mantel.
These instructions will help you build a classic and simple floating mantle that will look good in any room. This basic design is a great starting place. The ambitious DIYer might attach a fireplace surround, corbels, or layer trim to the piece to add a more refined style. If your home has existing built-ins or trims you’d like to match, feel free to embellish this basic design to add your touch to the final product.
Enjoy the beautiful addition to your fireplace safely. Check your local building code to ensure your mantel is properly placed. The national fire code requires all combustible material to be at least six inches from the firebox opening. Add an inch of clearing for every 1/8″ combustible material or trim protruding from the wall.
Measure the width of your firebox and add additional width to the mantel based on your preference. Typically, a fireplace mantle is 6-12″ wider than the firebox. For those with a masonry surround, you can choose to extend the mantle for the entire width of the brick or stone enclosure. Whatever size you choose, it should be appropriate to the space of the room and the fireplace itself. For this project, we are using a 66″ mantel.
Using a pocket hole jig, drill three 3/4″ pocket holes into one end of each of your 7.25″ pieces. These two pieces will form the sides of your mantel box.
Use a thin line of wood glue to affix the sides to the 66″ width of the mantel. The pocket hole should be facing towards the longer wood, with the holes facing in. This will conceal the holes once you’ve installed your mantel. Affix each side with 1-1/4″ pocket hole screws.
For each of the 1x8x64-1/2″ boards, drill 3 3/4″ pocket holes into each end of both boards. In the same way, you attached the sides of the mantel, apply a thin line of wood glue to the ends of these longer boards, and screw in using 1-1/4″ pocket hole screws to create both top and bottom.
In the four 5.75″ long pieces, drill a single 1/2″ pocket hole into one end of each.
These instructions are for staining, but feel free to finish your mantel in a way that best suits your space. There are many different finishing options available to explore.
In a well-ventilated area, sand your mantel. Start with 120-grit sandpaper and move in the direction of the grain. Move to 180-grit sandpaper and finish with 220-grit sandpaper until the surface of the wood is smooth to the touch. The initial sanding will open up the wood’s pores to more readily accept the stain; subsequent sanding leaves you with a better-finished surface for your fireplace’s centerpiece.
Clean up any dust with the sticky tack cloth. Be thorough, as remaining grit or sawdust can leave an uneven appearance in the finished stain.
For softwoods, like pine or cherry, begin by applying a pre-stain wood conditioner in a thin coat to prevent a blotchy appearance in your finished product.
Follow the directions of your favorite stain for best results, but typically you will want to stir your stain to ensure even distribution of the pigments.
Water-based stains, typically used with softwoods, are applied with foam or synthetic bristle brushes. Oil-based stains, usually used with hardwoods, are applied with a natural bristle brush or clean rag. If your wood has deep grain patterns that you want to bring out, work in a circular motion to rub the stain into the grain. Otherwise, work in the direction of the grain patterns.
Use the lint-free cloth to wipe off excess stain. Follow the directions on the can for the timing, but typically you can expect to remove oil-based stains in five to fifteen minutes and water-based stains within two minutes, as they dry much faster.
Allow the stain to dry thoroughly before applying a sealing coat. Water-based stains dry most swiftly and are ready for the next step in two to three hours. Oil-based stains can take four to six hours.
If you choose to apply the sealer, apply a thin first coat, allow it to dry thoroughly, lightly sand the surface with 220-grit sandpaper, wipe clean any debris, then apply the final coat.
In your 62″ long 2×4, drill three holes of 1/2″ diameter using a Forstner bit. Place one hole slightly off-center and the other two at each end approximately 3″ from the ends.
Find the center point of your firebox and the center point of the 2×4. Mark the center points clearly on the wall and board to ensure your mantel hangs in the right place.
Level your 2×4 and use the pre-drilled holes to mark the center of each against the wall. These marks will be where you need to drill the anchor holes.
Use a masonry drill bit and drill a 1/2″ hole about 3″ deep in each of the three marked places.
Hammer the anchors into both the 2×4 and the wall surface. Get a friend to help hold up the wood as you work. Once you position all the anchors, go back and tighten them with the wrench.
Finish by drilling the four shorter pieces of 2×4 into the length hung on your wall using the pocket screws and a line of wood glue. Place these two on each end and divide the center space into three roughly equal lengths with the remaining two. These additions will help provide additional support to the weight of your mantel box.
Hang the mantel box and drive 2″ wood screws into the sides and top of the mantel into the underlying 2×4 wood cleat to secure it.