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How to Build a Fireplace Mantel Shelf
  Free Woodworking Plans from Lee's Wood Projects

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Learn how to build a fireplace mantel shelf for your home. A custom made shelf mantle will adorn your fireplace and help achieve that special focal point of interest in your home. They are relatively easy to construct and mount. Even the novice woodworker can achieve a sense of accomplishment and have great success with this project. Many sizes and shapes of moldings are available so that one can easily vary the design of the fireplace mantle shelf to create the look you want.

How to Build A Fireplace Mantel Shelf
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Technical Information for Building a Fireplace Mantel Shelf

A . Materials List:

3/4" x 10" x 105"
Red Oak

Douglas Fir

Front Cove Molding
1" x 1 1/2" x 107"
Side Cove Moldings
1"x 1 1/2" x 11"
Front Crown Molding
6 1/4" x 105"
Side Crown Moldings
6 1/4" x 11"
1/2" x 5 3/4" x 96 1/2"
3/4" x 6 1/4" x 96 1/2"
Front Nailer
1/2" x 1 1/2" x 105"
Side Nailers
1/2" x 1 1/2" x 8 1/2"
1" x 3" x 100"

B. Cutting and Assembly Procedures:

  1. Use table & radial arm saws to cut lumber to proper widths & lengths for parts (A), (F), (G), (H), (I) & (J).
  2. Use jointer to joint the edges of same parts above to remove any irregularities.
  3. Glue and nail nailers (H) & (I) to under side of top (A). Make sure nailers are flush with the front & side edges of the top. Nail from the bottom side.
  4. Glue and nail brace (G) to top (A).
  5. Use power miter saw to cut the side cove moldings (C) to 45 degrees for the front corners and 90 degrees on the other ends so they will fit flush to the wall.
  6. Glue and nail side cove moldings (C) to the side edges of top (A). Make sure cove moldings are positioned flush with the top of top (A).
  7. Use a power miter saw to cut both ends of the front cove molding (B) to 45 degrees and then glue and nail into position. Nail to top (A) and side cove moldings (C).
  8. Use a power miter saw to cut the side crown moldings (E) to 45 degrees for the front corners and 90 degrees on the other ends so they will fit flush to the wall.
  9. Glue and nail side crown moldings (E) to the nailers (I) and brace (G).
  10. Use a power miter saw to cut both ends of the front crown molding (D) to 45 degrees and then glue and nail to front nailer (H) and side crown moldings (E).
  11. Cut bottom (F) to proper fit, and then glue and nail to brace (G). Also nail all crown moldings (D) & (E) to the bottom.
  12. Measure & mark wall for desired height and position of ledger (J). Use a power miter or radial arm saw to cut ledger to proper length and then attach to the wall using 2 1/2" drywall screws. Make sure ledger is level and screws go into wall studs. Use a stud finder to locate center of studs.
  13. Position mantel assembly on wall ledger (J) and secure by nailing top (A) to wall ledger.


  1. Use professional-strength wood glue.
  2. Use 1" finish nails to nail nailers to the top.
  3. Use 1 1/2'' finish nails to secure cove and crown moldings.
  4. Use 2" finish nails to secure mantel assembly to the ledger.
  5. Set all exposed nails below the wood surface using a nail set.
  6. A nail gun is preferred if available.

C. Sanding Procedure:

  1. Rough sand top (A) with an orbital sander and 80 grit sandpaper.
  2. Intermediate sand assembled mantel with an orbital sander and 120 grit sandpaper. (Intermediate sanding should be completed before attaching wood fireplace mantel shelf assembly to the wall ledger (J).
  3. Finish sand with 220 grit sandpaper (during the finish procedure).
  4. Hand sand all edges to desired finish.

D. Finish Procedure:

  1. Use plastic wood dough to fill all nail holes, cracks and defects.
  2. Finish sanding using 220 grit sandpaper.
  3. If stain is desired, apply with a brush and allow to penetrate 5-10 minutes and then remove excess with a clean rag. (Do not allow stain to dry before removing excess).
  4. Allow stain to dry for 6 hours and then repeat with a second coat.
  5. Allow second coat to dry for 8 hours.
  6. Apply a clear finish coat such as Varathane, Polyurethane, etc. using a pure-bristle brush. Allow to dry for 12 hours.
  7. Lightly hand sand using a 220 grit sandpaper.
  8. Apply second coat of clear finish.
  9. Allow to dry for 24 hours before using your fireplace mantel shelf.


  1. Be sure to match wood dough color to stain or finish color.
  2. Use a tack rag after each sanding procedure to remove dust.
  3. Wood fireplace mantel shelf design and finish changes can be made to fit your personal needs and preferences.
  4. Mantel dimension changes may be required to fit the size of your fire place and firebox opening.
  5. Bottom of mantel assembly should be a minimum of 12" above the fire box opening. To be sure you are complying with the code, it is suggested that you check with your local Building & Safety Department.

*Congratulations, your custom fireplace mantel shelf is finished and ready to use!

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