Things You'll Need
Fiberglass is a wonderful material. It doesn't break easily and lasts a long time. If your door is too big or long, it is reasonably easy to cut to the dimensions you need. Cutting fiberglass is a simple procedure, but in handling the door, you may need help because some are heavy. Fiberglass is also environmentally-friendly and reduces the number of trees cut to make a wooden door.
Measure the area with a measuring tape so you cut the right size for the door. Double-check the measurements before you make any cuts.
Transfer the measurements to the fiberglass door. Using a ruler, draw the lines you need to follow with a permanent marker.
Place masking tape over the area of fiberglass. This is to protect the fiberglass door as you cut.
Cut through the fiberglass door and masking tape, using a fine-tooth jigsaw blade. Make sure that the blade is set square. This will ensure that the cut is perfectly square.
Drill a hole in the fiberglass first if you need to cut a shape in the door for a cat or dog door. This will make the cutting easier to cut along the line you drew. If you are cutting down the height of a door, you do not need to drill any holes
File off the excess fiberglass, using a fine file. File in a downward stroke to prevent a ragged edge.
Remove the masking tape.
Put masking tape on the jigsaw table to keep the table from scratching the fiberglass door.
Wear a respirator to protect your lungs from the fumes. Also wear eye protection.