How to Trim an Opening for Your Attic Stairs

Updated February 21, 2017

Many households feature attic stairs, an easy and efficient way to access the attic. Attic stairs generally come in aluminium or fibreglass with varying sizes. Cutting out the opening for attic stairs is the first step toward attic stair installation and is a task suitable for most homeowners with a little bit of carpentry experience.

Go up into the attic and decide precisely where the stairs will be installed. Pick a spot where there is enough room to climb the stairs and safely get up into the attic. Make sure to position the attic stairs so they are running parallel with the ceiling joists. This will allow for proper installation.

Determine what size attic stairs will be installed. Remove any insulation around the area where the stairs will be installed. Lay down a few wood boards or planks to stand on during installation.

Mark on the ceiling joists where the attic stairs will be installed. Unless the joists are spread far apart, one of them will have to be removed for the stairs to be installed properly. Cut the joist with a reciprocating saw and remove it.

Measure the length of the two headers that will connect the two ceiling joists. Attach them with a drill and screws. Run the headers perpendicular to the ceiling joists. Use a T-square to verify the angles are correct. Measure the desired width of the rough opening on the headers and mark with a pencil. Cut a short joist with a mitre saw and attach it with screws between the headers, making sure it is square.

Cut out the drywall from the attic to the size necessary for the attic stairs. Follow along the headers and joists to complete the proper cut. Attach two 24-inch 1x3 furring strips with 3-inch screws on the far side of the rough opening. Fasten the screws up through the ledger board. With the opening trimmed out, begin installation on the attics stairs.


It is recommended to place a dust sheet on the floor underneath the drywall being cut out to avoid a mess when it is removed. Safety goggles are recommended when working with a reciprocating or mitre saw.


Always use a dust mask for proper ventilation when working in an attic with insulation.

Things You'll Need

  • Dust mask
  • Wood planks
  • Pencil
  • Reciprocating saw
  • Safety goggles
  • Drill
  • Screws
  • Tape measure
  • Dust sheet
  • Mitre saw
  • T-square
  • Ladder
  • 1x3 furring strips
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About the Author

Alexander Callos began writing in 2005 for "The Lantern" at The Ohio State University and has written for various websites, including Bleacher Report, Top Ten Real Estate Deals and Columbus Sports. He has published articles for CBS Sports, and other websites. He graduated in 2007 from The Ohio State University with a bachelor's degree in public affairs journalism.