How to Cut a Fiberglass Door

  • 2 hours
  • Beginner
  • 15
What You'll Need
Jigsaw Blade
Metal Ruler
Black Permanent Marker
Masking Tape
Drill Bit

A fiberglass door is a useful type of door which lasts for a very long time. If it needs to be cut down to size then you can do this by using a normal saw to cut through the fiberglass door. Cutting through fiberglass is actually very simple and easy, however, you must be careful that you don't breathe in the glass fibers.

Fiberglass is very easy to cut with a jigsaw.

Step 1 - Measuring

When cutting fiberglass doors it is important that you spend time measuring the size of the door so that you can make accurate cuts. Ensure that the measurements are as accurate as possible so that the door will fit properly in the doorway. Mark your measurements on the fiberglass door using a permanent marker.

Step 2 - Mask the Area

Mask the area of fiberglass that you are cutting out so that you can ensure it's fully protected. You might need to use more than one strip of masking tape depending on the width that you are cutting out. The masking tape will help to protect the fiberglass so that it can't get damaged or scratched when cutting it.

Step 3 - Drilling

Drill holes just outside of the line so that you can easily cut along the line using a jigsaw. These holes aren't necessary when you're cutting down the height of a door but they are required when you cut a shape out of the door for a cat flap for example.

Step 4 - Cutting the Fiberglass

Now the fiberglass needs to be cut by using a fine-tooth jigsaw blade. You will need to ensure that the blade is set perpendicular so that the cut is perfectly square. You might also like to put masking tape on the jigsaws table itself as this will stop it from scratching the surface of the door. Before you start cutting, put on your respirator mask and goggles—you absolutely do not want to breathe in fiberglass particles, or get them in your eyes!
Now put the jigsaw blade into one of the holes and start cutting along to the next hole. Try to follow the line as closely as possible. Never push the saw too quickly, instead, you need to wait for the blade to cut through.

Step 5 - Filing

Now use a fine file to grind off the excess fiberglass so that you are left with a perfectly clean cut. You should only file on a downward stroke to prevent a ragged edge.

Step 6 - Finishing Touches

Remove the masking tape and you will then be ready to start hanging the door as normal. If you need to trim any more off the door then simply follow the same guidelines in the future.