Fiberglass is a durable and attractive material that’s used in a variety of products.

It’s used in longbows, hammers, water pipes, storage tanks, and much more. Plus, they’re also used for roofing homes.

Fiberglass roof for garage
Fiberglass has resistance to heat and moisture which makes it great for roofing.

Fiberglass has many excellent qualities that make it suitable for roofing applications. These include high resistance to heat and moisture, as well as water and fireproof qualities.

They’re also quite low-maintenance if you compare them with other types of roofing materials.

However, they do need maintenance, and how exactly do you do that? You have to clean it, of course!

In this article, I’ll tell you how you can clean your fiberglass roof without too much effort or hassle. Read on!

Why Do I Need to Clean my Fiberglass Roof?

You clean your home to make it look nice and clean.

Same is the case when you clean your fiberglass roof. It’s a translucent material, giving your home a certain glow in the sunlight.

However, if you don’t clean your roof from time to time, it will accumulate dust and dirt.

Plus, if you have a corrugated fiberglass roof, it can get infested with lichen. This dirt will be visible when you look at your roof from inside the house.

Let’s have a look at all the things you need to do before you get to your roof.

What Should I Do Before Cleaning my Roof?

When cleaning the roof, I’m sure you’re aware of the dangers of falling from a height.

This is why you need to be extra careful while approaching your fiberglass roof.

Make sure you have a sturdy ladder that doesn’t wobble or swing as you climb. No matter how durable or strong the fiberglass, you need to be careful while stepping around it.

It’s always wise to inspect the roof for cracks or depressions beforehand.

Also, make sure you gather all your cleaning essentials. Carry them carefully to the roof so you don’t have to get down and up again.

Tips for a Proper Cleaning

To clean your fiberglass roof, all you need are two stiff brushes and a bucket with warm and soapy water.

Having an extended water hose reach the roof is a bonus. You can use a pressure washer as well.

First, use one of the stiff brushes to clean any dirt or debris on the surface. Make sure to sweep them into a garbage bag or dust collector, otherwise you run the risk of blocked gutters.

The next step is to dip the other brush into the warm soapy water. Now gradually clean the entire surface of your roof. You might have to brush a little harder if there is any grime or dirt.

Once done, you need to wash it off with clean water. For this, you might have to take another trip downstairs. This is why a garden hose comes in handy.

Be careful as the water and soap will make the roof slippery. So make sure you’re not wearing any footwear that has a weak grip.

If you have a pressure washer, you may not even need to brush the debris. However, be careful while using a pressure washer, as it can damage the adjacent wall trims or you can accidentally hose down your neighbor’s garden.

male using pressure washer to clean roof
Pressure washers are well suited to cleaning fiberglass roofs

If your fiberglass roof has lichen or any stubborn grime, there’s no need to worry. Simply:

  • Mix ¼ cup trisodium phosphate with a gallon of warm water and 1 quart of bleach.
  • Transfer this to a spray bottle or garden sprayer.
  • Spray the solution all over the roof, including every nook and cranny. Wait for 15 minutes, and then hose it down with a garden hose. Make sure to remove all of the solution from your roof.
  • If you notice mold on your fiberglass roof, mix 1 quart of bleach with 4 quarts of warm water.
  • Clean the mold-infected area with a soft brush, and then pour the bleach mixture onto it. This will kill all of the mold spores on the surface. Now you can clean it with the garden hose.

Maintenance Tips for a Fiberglass Roof

It’s best to get your fiberglass roof inspected regularly.

As I mentioned above, fiberglass roofs don’t require a lot of maintenance. But they can develop cracks or small holes over time, which can hamper their insulation qualities.

If you notice a hole or crack in your roof, call a roofing expert immediately.

One of the best ways to maintain your fiberglass roof is to apply new layers of coating. I’ll discuss this in the next section.

Can you Recoat a Fiberglass Roof?

When a new fiberglass roof is installed, it already has an acrylic or gel coating. This helps with insulation and waterproofing.

However, with time, this coating can wear off. This reduces the insulation of your fiberglass roof and also makes it prone to damage.

Therefore, the best way to prolong the life of your fiberglass roof is to recoat it with acrylic or gel coating. If you’re doing it yourself, let’s talk about the best and easiest way to go about it.

Before you do anything, make sure your roof doesn’t have any holes or cracks.

If there are any small ones, you can easily patch them up. If you’re going for gel coating, you’ll need a gel gun. Simply load the gun with the gel and follow the instructions.

Start with a heavy layer, and then wait ten minutes for it to settle.

Once this is done, apply a second layer, and then a third one. Lastly, apply the latex primer evenly on the surface, and use a sander to level it completely.

If you’re using acrylic coating, all you need is a paint brush or roller brush to apply it evenly. For effective coating, you need to apply at least three layers.


Keeping your fiberglass roof clean and well-maintained from time to time is important. It helps in insulating and moisture-proofing your home.

Cleaning the fiberglass roof doesn’t require too much effort, but make sure to take caution whenever you’re doing so.

I hope this article helps you understand how you can clean, maintain, and recoat your fiberglass roof on your own with minimal hassle.

If you like reading about stuff around the house, check out other similar articles on our website.

Thank you for reading, and have an amazing day!