Nearly 70% of exterior stains on fiberglass awnings come from dirt, mildew, and trapped debris. You can clean yours with a gentle rinse, mild soap, and a soft brush, but the order matters more than most people think. If you use the wrong pressure or cleaner, you can cloud the surface or force grime deeper. The safer method is simple, yet one step can make all the difference.
Gather the Right Fiberglass Awning Cleaning Supplies
Before you start, gather a soft-bristled brush, a garden hose, a pump-up sprayer, a sponge, and a mild dish soap solution so you can clean the fiberglass without damaging it.
Add safety gear like gloves and eye protection, then check material compatibility before you use any cleaner on your awning.
You can also keep a bucket, clean water, and a cloth nearby for quick wipeups.
If you’re targeting mold or stubborn grime, choose a diluted product that matches fiberglass care, not an abrasive mix.
A pump sprayer helps you apply solution evenly, while the sponge gives you control on delicate spots.
When you prep well, you protect the surface and feel confident joining other homeowners who keep their awnings looking cared for.
Rinse Off Loose Dirt and Debris
Start by sweeping off loose leaves, cobwebs, and other surface debris with a soft brush or broom.
Then hose the awning down gently to loosen dried dirt and soil. Keep the water pressure low so you don’t damage the fiberglass.
Remove Surface Debris
First, sweep off loose dirt, leaves, and cobwebs with a soft-bristled brush or broom, then hose the awning down thoroughly to flush away any remaining debris. Work from the top edge to the bottom so you don’t push grime into clean areas.
If you spot bird droppings or paint transfer, lift them gently now so they don’t harden and smear later. Check the underside too, especially over patios or seating areas, where dust often settles fastest.
Keep your strokes light; fiberglass can scratch if you press too hard. A quick, even prep makes the rest of the job easier and helps you protect the surface your group relies on for shade and curb appeal.
Once the loose material’s gone, you’re ready for the next cleaning step.
Use Gentle Water Rinse
Now rinse the awning with a garden hose to wash off the loosened dirt, dust, and soap residue. Keep the stream gentle so you don’t stress brittle fiberglass or force water under seams. Use low flow nozzles for steady control, and if you’re working overhead, try a misting technique to soften the rinse without blasting the surface. Move in smooth passes from top to bottom so runoff carries debris away.
| Tip | Why it helps | What to do |
|---|---|---|
| Gentle flow | Protects fiberglass | Use low pressure |
| Even rinse | Removes residue | Work in sections |
| Light mist | Reduces impact | Spray broadly |
Check corners, edges, and the underside for lingering suds. If water beads cleanly, you’re on track with the rest of us. Leave the awning open to air-dry fully before retracting it.
Mix a Mild Soap-and-Water Cleaning Solution
Mix a mild soap-and-water solution by adding a few drops of dish soap to a bucket or sprayer of warm water and stirring gently until it’s evenly mixed.
Keep the soap ratio light so you don’t leave residue on your fiberglass awnings. You’re aiming for a slippery, not sudsy, mix that lifts grime without stressing the surface.
Use microfiber sponges to test the solution on a small area first; they hold enough liquid to clean evenly and help you stay in control.
If the water still beads with dirt, add just one more drop of soap rather than overdoing it.
A simple, balanced blend gives you a reliable starting point and keeps your awnings looking cared for, clean, and ready for the rest of the job.
Wash Fiberglass Awnings With a Soft Brush
With your mild soap solution ready, dip a soft-bristled brush or sponge into the mix and wash the fiberglass in small, manageable sections. Use a light brush technique so you lift dirt without scratching the surface, and keep the strokes even and overlapping. If your tool has ergonomic handles, grip them firmly to stay comfortable while you work.
- Start at the top and move downward.
- Rinse the brush often to avoid spreading grime.
- Focus on one panel before moving on.
- Keep the awning wet as you clean.
You’re part of the smart-cleaning crew when you work patiently and gently. Finish each section with a low-pressure rinse, then move to the next area.
This steady method helps your awning look fresh without stressing the fiberglass.
Remove Mildew and Tough Stains
For mildew and stubborn stains, spray the fiberglass with a bleach-and-water solution or a sodium hypochlorite mix, then let it dwell long enough to break down the growth.
You’ll spot mildew identification by its gray, green, or black patches, often in shaded seams and along the underside.
After soaking, use a soft-bristled brush to work the surface in small sections, keeping your strokes light and steady.
For stain remediation, reapply the solution only where discoloration remains, then let it sit again before brushing.
Rinse thoroughly with a garden hose until the surface feels clean and soap-free.
If you’re part of a neighborhood that values tidy homes, this step helps your awning look cared for and keeps tough buildup from coming back.
Avoid Common Fiberglass Cleaning Mistakes
Even when mildew and stains start to lift, a few cleaning mistakes can damage fiberglass awnings fast. You want to protect your awning, not wear it out. Avoid abrasives, because scrub pads and harsh powders can scratch the finish and invite future buildup. Don’t use too much force, since brittle fiberglass can crack under rough handling.
Keep these common errors in mind:
- Skip steel wool and stiff brushes.
- Don’t mix chemicals without checking compatibility.
- Avoid letting cleaner dry on the surface.
- Prevent improper storage by retracting the awning only after it’s fully dry.
A gentle touch, the right solution, and patient care help you stay in the group of owners who keep their awnings looking sharp longer.
Rinse Fiberglass Awnings Thoroughly
Rinse the awning thoroughly with a garden hose to wash away loose dirt, soap, and chemical residue.
Use gentle water pressure so you don’t damage brittle fiberglass or force water into seams.
Keep rinsing until the runoff runs clear and the surface feels clean.
Rinse Away Loose Debris
Start by hosing down the fiberglass awning thoroughly to knock off loose dirt, leaves, cobwebs, and dried-on debris before you apply any cleaner.
This step helps you work with your crew on seasonal timing, since a dry, windless day makes cleanup easier and keeps wildlife deterrents from washing away.
Keep the rinse even and methodical so you don’t miss edges or the underside.
- Clear the top surface first.
- Rinse the underside next.
- Watch for trapped leaves and nests.
- Stop when the water runs clear.
If you’re tackling regular upkeep, this prep makes the rest of the job smoother and faster.
Once the loose material’s gone, you’re ready for cleaning without grinding grit into the fiberglass.
Use Gentle Water Pressure
Once the loose dirt is off, keep the rinse gentle and controlled so you don’t damage sun-brittled fiberglass. Use a garden hose with low pressure techniques, and choose nozzle selection that gives a soft fan, not a sharp jet.
Move methodically from top to bottom so you flush away soap, bleach, and grime without forcing water into seams or edges. If you’re cleaning with a partner, one of you can spray while the other watches for streaks and missed spots, which helps you work like a team.
Rinse until the water runs clear and no residue stays on the surface. Avoid pressure washers and keep the stream moving. After rinsing, let the awning air dry fully before you retract it or close it up.
Dry the Surface Without Scratching It
Let the awning air-dry completely before you retract it or close it up, since sun-weathered fiberglass can scratch easily when it’s still damp.
You’ll protect the finish by choosing shaded drying when the sun is strong and grit can bake on fast. If you need to speed things up, use clean microfiber towels and light pressure only.
- Blot, don’t rub, along the grain.
- Replace wet towels as soon as they load up.
- Keep zippers, snaps, and hardware from dragging across the surface.
- Check edges and seams for hidden moisture.
Work like part of the crew: move carefully, stay patient, and give the fiberglass time to dry fully before you stow it.
That extra care keeps the surface smooth and ready for the next cleanup.
Prevent Dirt and Mildew From Returning
To keep dirt and mildew from coming back, rinse your fiberglass awning on a regular schedule before buildup has time to set in.
You can also apply a protective sealant after cleaning to help repel moisture and grime.
Trim nearby foliage so leaves, pollen, and shade don’t keep feeding mildew growth.
Regular Rinse Schedule
Rinse your fiberglass awning on a regular schedule before dirt and mildew can build up, especially after storms, pollen season, or long dry stretches.
Keep seasonal timing in mind so you can stay ahead of grime and fit upkeep around your local climate and neighborhood regulations.
- Rinse with a garden hose on a low-pressure setting.
- Wash away dust, leaves, and bird droppings quickly.
- Check the underside, where moisture lingers longest.
- Let the awning dry fully before closing it.
A quick rinse every few weeks helps you protect your space and keep it looking cared for.
When you stay consistent, you’re part of the group that keeps awnings cleaner, longer, without extra work later.
Protective Sealant Application
After you’ve kept up with regular rinsing, you can add a protective sealant to help dirt and mildew release more easily on future cleanings. Choose sealant selection made for fiberglass, not wax that can haze or trap grime. Apply it after the awning is fully clean and dry; application timing matters most on a windless day with no rain for several hours.
| Step | What you do |
|---|---|
| 1 | Wipe off dust and residue |
| 2 | Test a small hidden spot |
| 3 | Spread a thin, even coat |
| 4 | Let it cure fully |
| 5 | Reapply as directed |
You’ll protect the finish and make your upkeep feel easier, cleaner, and more like a routine your whole outdoor space can rely on.
Trim Nearby Foliage
Trim back any branches, vines, or shrubs that crowd the awning so leaves, sap, pollen, and trapped moisture don’t keep feeding dirt and mildew. When you prune branches, you let sunlight and airflow dry the fiberglass faster, which helps your clean last longer. Keep the area tidy so you’re not fighting the same grime every season.
- Cut growth that touches the awning.
- Clear leaf litter after storms.
- Check for dripping sap or sticky residue.
- Manage pests that hide in dense foliage.
You’ll also reduce shade, which discourages mildew and algae. Keep clippings away from the frame, and inspect nearby plants every few weeks. A little routine trimming helps your awning stay brighter, cleaner, and ready for your next gathering.
Know When to Call a Professional Cleaner
If your fiberglass awning has years of built-up mold, heavy staining, or brittle sun damage, it may be time to call a professional cleaner. You’ll save time and protect the surface when grime won’t lift with gentle washing. Pros use low-pressure tools, the right detergents, and safe dwell times, so you avoid cracking or streaking.
They also follow safety standards and can handle ladders, overspray, and runoff more confidently than most homeowners. Before you book, ask about insurance considerations, especially if the awning sits over a doorway or shared space.
A trusted cleaner can restore curb appeal and help you feel proud of your home again. If the job feels too large, too high, or too risky, you’re not alone in calling for backup.
Frequently Asked Questions
How Often Should Fiberglass Awnings Be Cleaned?
Clean fiberglass awnings every two to three months, and inspect them each season. If you notice mold, heavy dirt, or pollen accumulation, clean them more often.
Can I Use Bleach on All Fiberglass Awnings?
No. Bleach can damage the finish on some fiberglass awnings and cause weakening similar to how harsh weather can wear a sail. Test a small hidden area first. If the finish is affected, use a mild, nonbleach cleaner and protect the coating by cleaning gently.
Should I Clean the Awning Underside Too?
Yes. Focus on the area directly above seating and any other spots that collect dirt. Cleaning removes grime, mold, and debris, improves airflow, and helps protect any insulation or materials installed under the awning. Use a soft brush and a gentle rinse.
Is Low-Pressure Washing Safe for Old Fiberglass?
Yes. Treat the spray like a gentle rain: use a low pressure setting, keep the nozzle several feet from the fiberglass, avoid hot water, and use a mild detergent or cleaner formulated for awnings. These steps help preserve the surface and protect an older fiberglass awning.
How Long Should the Awning Dry Before Retracting?
Let the awning dry for at least 4 to 5 hours; for complete drying, wait overnight. This prevents loss of fabric tension, sticking, and trapped moisture or stains.
