Step 3: Notch and install the stool

trimming out a window «»
Mark the stool's inside edge 1 inch from each end and place it across the opening. Mark where the stool’s edge meets the inside edge of the jambs. Set a square at those marks and draw "jamb lines" across the top of the stool. Rout the desired profile into the stool's edge and ends.

Align the jamb lines with the jambs' inside edges. Set the compass to the distance from the stool’s back edge to the sill trim. Hold the compass point against the wall and scribe lines from each end of the stool to the jamb line.

Following the scribe lines, cut a notch into each end of the stool with a jigsaw. Test fit the stool; fine-tune it with a jigsaw, chisel, or sandpaper. Apply a bead of glue to the sill.

Facenail the stool to the sill with four 18-gauge nails (or 4d finish nails).
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    Tools List

    • finish hammer
      20-ounce finish hammer
    • hand plane
      Hand plane,
      for trimming jamb extensions
    • 16-foot tape measure
      Measuring tape
    • router
      Router,
      for making stool profile
    • random orbit sander
      Random-orbit sander,
      or hand sanding block
    • jigsaw
      Jigsaw,
      for notching stool and profiling apron
    • pneumatic finish nailer
      Pneumatic nailer,
      for attaching casing
    • pencil compass
      Compass,
      for transferring marks and reveal lines
    • table saw
      Table saw,
      for cutting rabbet in bottom of stool
    • try square
      Square,
      for marking casing, stool, and apron
    • utility knife
      Utility knife or chisel,
      for trimming drywall and adjusting fit of stool
    • miter saw
      Miter saw,
      for crosscutting trim pieces to length
    • nailset
      Nail set (to recess heads of hand-driven nails
    • drill
      Drill with 1/16-inch-diameter bit,
      for making pilot holes before hand nailing

    Shopping List

    1. WOOD MOLDING

    2. CARPENTER'S GLUE

    3. PENCIL

    4. PAINT OR STAIN

    5. 120-GRIT SANDPAPER

    6. WOOD PUTTY

    7. 4D AND 8D FINISHING NAILS