How to Build a Pediment

Amanda Ballard Coates

Building a pediment over your windows or door can add character and an architectural detail to the plain facade of a home. A pediment is a low-pitched gable or medallion on the front of a building, usually above a window or door. Pediments can be plain or have ornate details and are usually seen on historic homes.

  1. Measure for the desired placement of pediment. Use level to draw a level line at height of pediment peak.

  2. Next, mark the top of the door frame and measure from this mark to ground level.

  3. Use measurement from previous step to cut pilasters/columns. Pilasters/columns should reach up to the top of the door frame.

  4. Cut pilasters/columns to desired size. If your door frame is the standard 80 inches, then you should cut them to meet this measurement. Be sure to cut with hand saw or chop saw on the far side of the measurement line to ensure the finished column/pilaster is the desired size.

  5. Mark holes in the center of the pilaster/columns at top and bottom. If your column/pilaster measures 6 inches, the hole should be at the 3-inch mark at top and bottom. Attach column/pilaster on outside of door frame with a screw. If screwing into masonry or brick, be sure to use masonry screw anchors.

  6. Place pediment piece atop of the pilasters/columns and secure with screws. Construction adhesive is another option since the pediment is not weight-bearing. Pediments can be purchased in many shapes and styles already finished. This will save you time building and is ideal for the maximum impact. A store-bought pediment is a good option for first-timers and comes in a variety of styles from really plain to extremely detailed pieces.

  7. Use caulk to fill in screw holes and around the edges of the pediment piece. This will seal any cracks and keep water out. Caulking the seams will extend the life of your pediment and keep it from rotting.

  8. Lightly sand caulked areas smooth. Most pediments and columns come pre-finished in white. You may paint pediment and columns any color you desire.