How to Paint a Fiberglass Garage Door

A home garage door, painted purple.
  • 3-5 hours
  • Intermediate
  • 100-250
What You'll Need
Masking tape
Lint-free cloth
Brillo pad, wire wool, or soft, abrasive pad
Dust mask
Bonding primer paint
Paint brushes
Oil-based exterior paint

Color is the simplest change you can make to your home to refresh its look and enhance its curb appeal, even on your garage. A fiberglass door can be painted, but there are some things to consider and some tips to follow for a job well done.

Step 1 - Check the Existing Door

If you have decided to paint your fiberglass garage door, you will need to check the material's stability first to make sure it is not irreparably damaged. Fiberglass is considerably more fragile than alternative materials like vinyl and it tends to degenerate over long periods of time. Before you begin, decide whether the garage door is too weak or too brittle to paint over so you know if it needs to be removed and replaced.

You can choose to paint your garage door while it is still attached or you can remove it. Remove the fixtures and handle as well, or mask them off, if the stability of your door checks out.

Cleaning a garage door

Step 2 - Clean the Surface

Clean the door of any dirt and debris by using a gentle solution of soap and water and a lint-free cloth. Grime on the door will prevent the paint from adhering properly and will likely cause it to crack or peel shortly after the job is finished. Leave it to dry completely before you begin priming it. You can wipe it dry with a large cloth or, if the weather permits, just let it air dry.

Taped paper creating a mask around a garage door for painting

Step 3 - Mask the Door

If you have chosen to leave the door attached, mask off areas that do not require primer or paint to protect them from being coated. If the frame around the garage door is not made from the same material, you may not want paint marks to accidentally get on it.

Sanding a garage door with a Brillo Pad

Step 4 - Sand

Some types of fiberglass garage doors are not suited to heavy sanding, so you should use a Brillo pad, wire wool, or soft abrasive paper to just lightly rough up the surface to get a texture for the primer to grip. Wear a dust mask when you do this part of the project.

Step 5 - Coat the Surface with Primer

You must use a good bonding primer. Fiberglass has a somewhat paint-resistant surface which can affect the longevity of the coat you put on it. That is not to say that you cannot paint fiberglass, but do take the correct precautions and choose a good primer to increase the staying power.

Prime the garage door with the brush. There is no grain to follow like with wood, but do attempt to maintain steady and even brush strokes. The end result you are trying to achieve is to make the door appear new but not as if it has been painted. You can also opt to use spray paint, which will leave no brush strokes at all, if you so choose.

Spray painting and brush painting a garage door

Step 6 - Paint the Top Coat

Allow plenty of drying time before you apply the topcoat of paint. Outside conditions will naturally dry the paint quicker, especially if the weather is reasonably warm and the air dry. Atmospheric conditions will also affect whether you should paint. Lower temperatures are not strongly recommended for painting, nor are extremely high temperatures.

Paint the garage door using the same method you used for priming. Be mindful of not leaving obvious brush strokes. It is important that you use a good oil-based exterior paint for a durable finish, but if you are not sure what type to use, ask at your local home improvement store for some advice.

With that, your garage door simply needs to be fitted back into place and the job will be complete.