How to use a jamb saw

Written by david brown
  • Share
  • Tweet
  • Share
  • Pin
  • Email
How to use a jamb saw
A jamb saw is a useful addition to your flooring tool kit. (Parquet floor image by Einar Bog from

A jamb saw, also known as an undercut saw or flush cut saw, is used to cut the bottom of existing door jambs flush with the top of a newly installed hardwood floor. Jamb saws come in both rotary and reciprocating versions. Electric jamb saws are adjustable both for depth of cut and for the height of the cut. Most well-stocked rental yards have jamb saws available. Exact adjustment methods vary from saw to saw; consult your owner's manual for how to adjust your saw.

Skill level:

Things you need

  • Safety glasses or goggles
  • Jamb saw
  • Scrap of flooring material
  • Hammer
  • Nail set

Show MoreHide


  1. 1

    Use a scrap piece of your flooring material as a guide to set the height of the saw blade. Adjust the saw so that the top of the blade is level with the top of your flooring material.

  2. 2

    Adjust the depth of cut to slightly deeper than the thickness of the door jamb you will cut. Most door jambs are 11/16 inch thick, so setting the saw to a depth of 7/8 inch should be about right.

  3. 3

    Look for any nails in your line of cut. If you find nails, use a nail set and a hammer to drive them in deeper than your depth of cut.

  4. 4

    Place the saw on the subfloor, adjacent to the door jamb. Start the saw, and let the blade come up to speed before beginning your cut. Sliding the saw on the subfloor, plunge the blade into the casing on the left side of the door jamb and, continuing in a counterclockwise motion, cut the left casing. Cut the door jamb and the right side casing.

Tips and warnings

  • Jamb saws are also used to cut a kerf or notch in baseboard and cabinets to accept the edge of a vinyl floor. Set the blade on its lowest setting, and make your cut ¼ inch deep.
  • Flush cut hand saws are also available. To cut a door jamb with a hand saw, place a scrap of flooring on the subfloor, flush to the door jamb. Slide the saw along the top of the scrap to make your cut.
  • Always wear safety glasses or goggles when using power tools.

Don't Miss

  • All types
  • Articles
  • Slideshows
  • Videos
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the site, you consent to the use of cookies. For more information, please see our Cookie policy.