How to Install Sheetrock Over Rigid Foam Board

Rigid foam board insulation is commonly used to help insulate homes.

Drywall can be installed over rigid foam board insulation.Drywall can be installed over rigid foam board insulation.
With varying sizes of thickness, this insulation is a great way to save on energy costs. This type of insulation is commonly installed in basements over concrete block, and installing drywall on top of it can give the room a finished and elegant look. Installing drywall over insulation is similar to installing drywall into regular studs; however, there are some added steps to ensure the drywall is properly installed.

Multiply the width of the wall by its height to determine how many sheets of drywall will be necessary to cover the insulation.

Mark a horizontal chalk line along the foam board 3 inches from the top of the wall, followed by a line 3 inches from the bottom. Measure from the bottom to the direct center and snap another chalk line. Add one more chalk line directly between the middle line and the top line. The fifth and final line will go between the middle line and the bottom line.

Line up the first furring strip on the bottom chalk line. Drill a hole 5 inches deep with a masonry bit and hammer drill through the insulation and into the concrete walls. Begin at one end and drill a hole every 16 inches. Repeat this process for each of the five furring strips. Drive 4-inch long spring spikes with a hammer into each of the holes.

Connect 1x3 furring strips vertically to the horizontal strips. Space the strips every 16 inches on center across the entire length of the wall. Drill in drywall screws spaced every 16 inches vertically.

Line up the first piece of drywall along the wall. If the sheet needs to be cut, use a T-square and cut along the straight edge with a utility knife. Bend the piece of drywall down and it will snap. Cut the back side to break it off completely.

Drill drywall screws beginning at the top left corner into the 1x3 vertical furring strips. Position the screws every 16 inches all the way down the entire sheet. Go around the entire sheet of drywall, screwing into the top, bottom and the other side. Repeat this process for each sheet, cutting to fit when necessary.

Mud over the seams and screws holes with joint compound and a taping knife. Spread out the mud with a knife to cover any gaps. Smooth out the compound by sanding down the area with a drywall sander.

Things You Will Need

  • Tape measure
  • Chalk line
  • 1x3 furring strips
  • Drill
  • Masonry bit
  • Hammer drill
  • 4-inch long spring spikes
  • Hammer
  • Drywall screws
  • T-square
  • Utility knife
  • Joint compound
  • Taping knife
  • Drywall sander


  • Sheets of drywall generally come in 4-by-8-foot sheets, covering 32 square feet.

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.