Mold on Sunbrella comes off with a mild soap solution and a soft brush, without bleach or pressure washers that damage the fabric

Sunbrella is a solution-dyed acrylic fabric designed to resist mold and mildew better than cotton canvas, but it is not mold-proof. When mold does appear—usually as dark spots or a thin film—you can remove it at home with materials you likely have in your kitchen. The key is using the right cleaning method so you do not weaken the fabric's water-resistant coating or push mold spores deeper into the weave.

The process takes about 30 minutes of active work, plus drying time. You do not need to remove the fabric from its frame for light to moderate mold, though you will need access to both sides if the mold has soaked through.

Key Takeaways

  • Mix warm water with a small amount of mild dish soap—never use bleach, which damages Sunbrella's finish and can cause permanent discoloration.
  • Scrub gently with a soft-bristled brush in the direction of the fabric weave, working from the back side first if mold is visible on both sides.
  • Rinse thoroughly with clean water until no soap remains, because leftover soap traps moisture and can cause mold to return faster.
  • Let the fabric air-dry completely in sunlight and moving air before storing or using it again, which typically takes 24 to 48 hours depending on humidity.
  • Prevent future mold by storing Sunbrella items in a dry location and wiping them down after rain or heavy dew.

What You Need Before You Start

Gather these items before you begin: a bucket, warm water, mild dish soap (Dawn or similar—nothing with bleach or antibacterial additives), a soft-bristled brush (an old toothbrush works for small spots; a soft deck brush for larger areas), clean towels or rags, and a hose or spray bottle for rinsing. Do not use a pressure washer, stiff brush, or any abrasive scrubber, as these will fray the fabric and damage its protective coating.

If the mold covers more than half the fabric or has a musty smell that does not fade after cleaning, the mold may have penetrated deep into the weave or the backing. In that case, professional cleaning is more effective than home treatment.

The Cleaning Process: Step by Step

Start by mixing one part mild dish soap with four parts warm water in your bucket. The solution should feel slippery but not soapy—you want just enough soap to break down the mold, not so much that it leaves residue. Test the solution on a hidden corner of the fabric first to make sure it does not cause discoloration.

Dip your soft brush into the solution and scrub the moldy area gently, using short strokes in the direction of the fabric weave. Work from the back of the fabric first if mold is visible on both sides—this pushes the mold out toward the front rather than deeper in. Do not scrub hard or in circles; light, directional pressure is enough. For stubborn spots, let the soapy water sit on the mold for 5 to 10 minutes before scrubbing, which gives the soap time to break down the mold's grip.

Once you have scrubbed the entire moldy area, rinse it thoroughly with clean water. Use a hose on low pressure or pour water from a bucket—do not use a pressure washer. Rinse until the water runs clear and you cannot smell soap anymore. Leftover soap traps moisture in the fabric and creates conditions for mold to return, so this step is not optional.

Drying Your Sunbrella Properly

After rinsing, hang or lay the fabric flat in direct sunlight with good air circulation. Sunlight kills mold spores and helps dry the fabric faster. If the fabric is on a frame (an umbrella, awning, or cushion cover), position it so air can flow on both sides. In dry climates, Sunbrella dries in 12 to 24 hours; in humid areas, it may take 48 hours or longer.

Do not store the fabric until it is completely dry. Even slightly damp Sunbrella will develop mold again within days. If you are drying it indoors, open windows and use a fan to move air across the fabric. Avoid enclosed spaces like closets or storage bags until the fabric has been dry for at least 24 hours.

Why Bleach and Pressure Washers Damage Sunbrella

Bleach breaks down the acrylic fibers and strips away the finish that makes Sunbrella water-resistant. Even diluted bleach can cause permanent yellowing or white spots that do not wash out. Pressure washers, even on low settings, force water and mold spores into the fabric's backing and can separate the coating from the weave, creating weak spots that tear easily.

Some people use a 10 percent bleach solution on canvas or cotton, but Sunbrella is not canvas. Its synthetic fibers and protective coating require gentler treatment. Stick with soap and water, and you will preserve the fabric's performance for years.

Preventing Mold from Coming Back

Mold grows on Sunbrella when the fabric stays damp or wet for extended periods. After rain or heavy dew, wipe the fabric dry with a clean towel if you can reach it. If the fabric is on an umbrella or awning, open it fully to let air circulate underneath and dry the underside.

Store Sunbrella items in a cool, dry place—not in a damp basement, garage, or sealed storage bag. If you must store fabric that is still slightly damp, leave it unfolded or loosely rolled so air can move through it. In humid climates, a small fan or dehumidifier in the storage area helps prevent mold from starting in the first place.

If you live in a very humid area or near salt water, inspect your Sunbrella items every few weeks during warm months. Catching mold early, when it is just a few small spots, takes minutes to clean and prevents the larger problem that requires professional help.

When to Call a Professional Cleaner

Professional upholstery or fabric cleaners have access to stronger, fabric-safe cleaning solutions and equipment that can remove mold that home cleaning cannot reach. Consider professional cleaning if the mold has a strong musty smell that does not fade after your cleaning attempt, if it covers more than half the fabric, if it has soaked through to the backing, or if the fabric is part of an expensive piece of furniture or a custom awning.

Professional cleaners also know how to dry the fabric properly without damaging it, which matters for large pieces like boat covers or patio awnings that are hard to dry at home. The cost is usually between $50 and $200 depending on the size and severity, but it is worth it if the alternative is replacing the fabric.

Frequently Asked Questions

Can I use vinegar instead of soap and water?

Vinegar is acidic and can damage Sunbrella's finish over time, so it is not recommended. Mild dish soap and water is gentler and just as effective for mold that has not deeply penetrated the fabric. If you want a natural alternative, some people use a solution of water and a small amount of baking soda, though soap works faster.

Will mold come back if I clean it once?

Not if you dry the fabric completely and store it in a dry place. Mold returns only if the fabric stays damp or if it is stored in a humid environment. If mold keeps coming back to the same spot, the fabric may have a moisture problem—check for leaks, poor drainage, or air circulation issues in the area where you store it.

Is it safe to use Sunbrella cleaner products instead of dish soap?

Sunbrella-brand fabric cleaner is designed for the material and is safe to use. Follow the product instructions, which are usually similar to the soap-and-water method. Commercial fabric cleaners cost more than dish soap but may work slightly faster on stubborn mold. Either method is fine as long as you avoid bleach and pressure washers.

How long does it take for mold to damage Sunbrella permanently?

Mold itself does not permanently damage Sunbrella if you remove it within a few weeks. However, if mold sits for months, it can stain the fabric or weaken the fibers in that area. The sooner you clean it, the better the result. Stains that remain after cleaning are usually cosmetic and do not affect the fabric's water resistance.

Can I dry Sunbrella in a dryer or with heat?

No. High heat can damage the acrylic fibers and the protective coating. Air-dry only, in sunlight if possible. Sunlight is actually beneficial because UV rays kill mold spores, so drying in direct sun is better than drying in shade.