How do I Install Inside Access to a Crawl Space?

If your house has a crawl space, you may not want to cut through an exterior house wall to provide an access panel unless it will be well hidden.

One alternative is to install an access to the crawl space inside the house, in an out-of-the-way place such as a closet or laundry room. An interior access won't decay due to exposure to the elements as an outdoor access panel might. This project can be done by a homeowner with enough experience to operate a circular saw.

Locate the spot on the floor inside a closet or another inconspicuous place to cut a hole for an access panel. Pull any carpeting away from the baseboard to reveal the floor. Hover the stud finder over the area according to the manufacturer's instructions. This locates the floor joists along with any duct work or pipes under the floor. Mark the floor joists with a pencil.

Place the framing square along one of the floor joists and draw a 22 1/2-inch line on the floor with a pencil. Move the framing square to the floor joist across from the first and draw a line in the same manner.

Slide the framing square to one end of one line and draw a perpendicular line over to the next floor joist. Repeat this on the other end of the line, resulting in a square that is 22 1/2 inches by 22 1/2 inches.

Set the circular saw cutting depth to 2 inches. You will notice a mark on the front of the plate indicating where the saw blade will cut. Align that mark with one of the lines on the floor. Set the front of the plate on the floor while holding the back of the saw up enough to keep the blade from touching the floor. Turn on the saw and slowly lower the blade through the floor.

Cut the other lines with the saw and remove the wood. Measure the opening in the floor and cut a piece of plywood to fit. If the cutout had two layers of floor board, you will need to cut two pieces of plywood instead of just one. Still using the circular saw, cut two pieces from the 2-inch by 4-inch by 48-inch lumber to 22 1/2 inches in length.

Hold the lumber against the floor joist so the top of the lumber is even with the top of the floor joist. Secure the lumber to the floor joists with the 2 1/2-inch drywall screws; one on either end and one in the middle. Set the piece(s) of cut plywood inside the opening to rest on top of the two pieces of 2-inch by 4-inch lumber.

Drill a finger hole in the plywood access panel with a 1 1/4-inch paddle bit. Lay the carpet back in place. If cutting through tile, sand the cut edges with a sanding block and 100-grit sandpaper.

Things You Will Need

  • Stud finder
  • Framing square
  • Pencil
  • Circular saw
  • Measuring tape
  • 1-2 pieces of 24-inch by 30-inch by 3/4-inch plywood
  • 1 piece of 2-inch by 4-inch by 48-inch lumber
  • Variable speed drill
  • Phillips head screw tip
  • 6 drywall screws, 2 1/2-inches long


  • Sand the plywood before applying a finish, if desired


  • Do not leave power tools within the reach of children.
  • Do not leave the access hole open while children and pets are present.

About the Author

Michael Straessle has written professionally about the construction industry since 1988. He authored “What a Strange Little Man,” among other books, and his work has appeared in various online publications. Straessle earned a Bachelor of Arts from the University of Arkansas at Little Rock in professional/technical writing.