How to Cut Rigid Foam

Straight Cuts

• 1

  Arrange the piece of rigid foam so it will be convenient to reach and cut the line. You can place the foam on the floor, lean it against a wall or set it on a work surface such as a saw horse.

• 2

  Measure each end of the rigid foam and make marks to indicate where to cut the material.

• 3

  Snap a chalk line from one mark to the other. Scribe along a straight edge, such as a 4-foot level or a piece of wood, to create a cutting line as another option.

• 4

  Adjust the utility knife blade so it will penetrate through half of the rigid foam's depth.

• 5

  Cut the rigid foam along the marked line, starting at one end and working across to the opposite side.

• 6

  Bend the rigid foam gently on the opposite side of the scribed cut until the material snaps in half.

Radius Cuts

• 7

  Mark the radius line on the face of the rigid foam using a compass tool. For larger objects, make a mockup of the cutout on a piece of cardboard and lay it on the rigid foam. Trace around the mockup directly onto the face of the rigid foam.

• 8

  Insert the tip of a keyhole saw through the rigid foam along the cutout line.

• 9

  Moving the keyhole saw in an up-and-down motion, cut along the radius cutout line until the task is complete.