• In this video, This Old House general contractor Tom Silva shows how to build window boxes.

    1. Use circular saw and clamped-in-place straightedge guide to cut window-box parts to size from medium-density overlay.
    2. Use drill/driver to drill counterbore and screw-pilot holes, then assemble the box parts with polyurethane glue and 2-inch-long ceramic-coated deck screws.
    3. Attach two galvanized-steel right-angle brackets to the house wall directly below a window. On vinyl siding, be sure to insert two small wood blocks behind each bracket to avoid crushing the siding.
    4. Drill pilot holes through the siding and secure each bracket to the house wall with 2-inch-long ceramic-coated deck screws.
    5. Drill six -inch-diameter weep holes through the bottom of the window box.
    6. Fill all screw holes with auto-body filler, then sand flush with random-orbit sander.
    7. Prime and paint the box with exterior-grade house paint.
    8. Set window box onto brackets and secure by driving ¾-inch galvanized or stainless steel screws up through the brackets and into the bottom of the box.
    • 2 to 4 hours to build and install one window box
    • $60 for redwood or $45 for medium-density overlay for an average-size window box
    • Difficulty: Moderate
      requires basic carpentry skills
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      Video Directory

      Selected Topic/Section

      Tools List

      • circular saw
        Portable circular saw
      • hand clamps
        Clamps and straightedge guide
      • drill
      • random orbit sander
        Random-orbit sander fitted with 120-grit disk
      • putty knife
        Putty knife
      • paint brush and roller
        Paintbrush and trim roller

      Shopping List

      1. ¾-inch medium-density overlay (MDO)

      2. Galvanized right-angle brackets

      3. Polyurethane glue

      4. 2-inch-long ceramic-coated deck screws

      5. Auto-body putty

      6. Primer and paint

      7. ¾-inch galvanized or stainless steel screws