How To Clean Outdoor Furniture Covers: The Complete Restoration And Maintenance Guide

Clean outdoor furniture covers by removing loose debris with a soft-bristle brush, then scrubbing the fabric with a solution of mild dish soap and lukewarm water under 100°F (38°C). For mold and mildew removal, apply a diluted vinegar-and-water mixture on polyurethane-backed fabrics, or a mild bleach solution exclusively on solution-dyed acrylics. Always air-dry the covers completely before storage or placement to prevent structural delamination and fiber rot.

Pre-Cleaning Assessment and Equipment Preparation

Before initiating the cleaning process, you must identify the structural composition of your outdoor furniture covers. Most high-performance covers are manufactured from solution-dyed polyester, solution-dyed acrylic (such as Sunbrella), vinyl (PVC), or heavy-duty cotton canvas. Polyester and vinyl covers frequently feature an inner thermoplastic polyurethane (TPU) or polyvinyl chloride (PVC) waterproof backing. This backing is highly sensitive to thermal stress, mechanical abrasion, and aggressive chemical solvents.

Improper cleaning methods—such as using boiling water, heavy spin cycles, or harsh alkaline detergents—will dissolve protective coatings, delaminate waterproof backings, and strip the fabric of its factory-applied Durable Water Repellent (DWR) finish. To ensure a successful restoration without compromising the structural integrity of the material, gather the necessary tools and establish your working environment according to the specifications below.

Essential Gear, Materials, and Benchmarks

• Scrubbing Tools: Soft-bristle nylon brush, horsehair brush, or non-abrasive microfiber sponge. Avoid wire brushes or stiff-bristle utility brushes.
• Cleaning Agents: Mild pH-neutral dish soap (e.g., blue Dawn), liquid laundry detergent free of dyes and perfumes, distilled white vinegar (5% acidity), and household liquid bleach (sodium hypochlorite 5.25%–6.15%, for bleached-safe fabrics only).
• Protective Equipment: Nitrile gloves, protective eyewear, and a clean plastic drop cloth to protect lawns or patio surfaces.
• Water Source: Standard garden hose with an adjustable spray nozzle. Do not use a high-pressure washer, as the concentrated PSI will shred synthetic fibers and strip waterproof laminates.
• Estimated Budget: $15 – $40 for cleaning agents and protective sprays.
• Estimated Duration: 1 to 3 hours of active labor; 12 to 24 hours of passive drying time depending on ambient humidity and sunlight.

Step-by-Step Outdoor Cover Deep Cleaning Protocol

Follow this systematically engineered protocol to safely clean, decontaminate, and re-waterproof your outdoor furniture covers.

Step 1: Dry Debris Removal and Inspection

Lay the covers flat on a clean, dry outdoor surface, preferably over a clean tarp or concrete patio. Do not perform this step on grass or dirt, which can introduce organic contaminants. Use a dry, soft-bristle nylon brush to sweep away loose surface dirt, dried leaves, pine needles, bird droppings, and insect nests. Work systematically from the top of the cover downward. Pay close attention to the seams, pockets, vents, and elastic drawcords where organic matter accumulates. Once brushed, inspect the interior backing for signs of cracking, peeling, or mold growth.

Step 2: Initial Spot Treatment for Organic Stains and Sap

Before wetting the entire cover, target localized stains.

• Tree Sap: Apply a small amount of isopropyl alcohol (70% concentration) directly to a clean microfiber cloth. Gently blot the sap spot. Avoid rubbing, which spreads the sap deeper into the fabric weave. Once the sap softens, scrape it away gently with the edge of a plastic spoon.
• Bird Droppings and Pollen: Mix 1 tablespoon of liquid dish soap with 2 cups of warm water. Apply the solution directly to the stain, let it sit for 5 minutes, and brush gently in a circular motion with your soft-bristle brush.

Warning: Never use acetone, mineral spirits, or petrol-based solvents on polyester or vinyl-backed covers. These chemicals will immediately melt the synthetic fibers and dissolve the waterproof polyurethane backing.

Step 3: Deep Cleaning with a Neutral Detergent Solution

Prepare your primary washing solution in a 5-gallon bucket. Mix 1/4 cup of mild, pH-neutral dish soap or dye-free laundry detergent with 3 gallons of lukewarm water. Ensure the water temperature does not exceed 100°F (38°C).

1. Use your garden hose to thoroughly pre-wet the entire cover with cold water.
2. Dip your soft-bristle brush into the cleaning solution and apply it generously to the cover's surface.
3. Scrub the fabric using light, circular motions. Work in 3x3 foot sections to ensure thorough coverage.
4. Focus extra attention on areas that contact the furniture edges, as these zones experience the highest concentration of friction and soil accumulation.
5. Flip the cover inside out. If the inner backing is polyurethane or vinyl, wipe it down gently using a soft microfiber cloth dipped in the soapy water. Do not scrub the backing with stiff brushes, as this causes micro-tears and peeling.

Step 4: Targeted Mold and Mildew Remediation

If your covers exhibit black, green, or grey spotting, they are contaminated with mold or mildew. The cleaning approach depends strictly on the fabric material:

• For Solution-Dyed Acrylic (e.g., Sunbrella): Prepare a chlorinated solution containing 1 cup of liquid bleach, 1/4 cup of mild dish soap, and 1 gallon of cool water. Apply this solution to the stained areas and allow it to penetrate the fibers for 15 minutes. Scrub gently with a soft brush, then rinse completely.
• For Polyester, Vinyl, or PU-Backed Fabrics: Do not use bleach, as it degrades polyurethane coatings. Instead, mix 1 part distilled white vinegar with 3 parts warm water. Spray the solution generously over the mold colonization. Allow it to sit for 30 minutes. The acetic acid in the vinegar will kill the mold spores at the root. Scrub gently and rinse.

Pro-Tip: Always perform a spot-test with cleaning solutions on a small, inconspicuous area of the cover (such as an interior hem) to verify colorfastness and material stability before general application.

Step 5: Thorough Rinsing and Drying

Soap residue left within the fabric weave acts as a magnet for dirt, dust, and organic matter, which accelerates mold re-growth. Run a low-pressure stream of clean water from your garden hose over the cover. Work from the top down, washing all soap suds toward the ground. Continue rinsing until the runoff water is completely clear and free of bubbles.

To dry, hang the covers over a heavy-duty clothesline, a railing, or clean patio chairs in a well-ventilated, shaded, or partially sunny area.

Warning: Do not place outdoor furniture covers in a mechanical clothes dryer. The intense heat of a dryer—even on low settings—will shrink synthetic fibers, warp vinyl components, and melt waterproof backings, rendering the covers unusable.

Step 6: Restoring the Durable Water Repellent (DWR) Coating

Repeated cleaning cycles and UV exposure gradually deplete the factory-applied water-repellent finish on the cover's exterior. To test if your DWR coating is intact, splash a few drops of water onto the dry fabric. If the water beads up and rolls off, the coating is functional. If the water saturates the fabric and darkens the color, you must apply an aftermarket fabric protectant.

1. Ensure the cover is entirely clean and 100% dry.
2. Move the cover to a well-ventilated outdoor area away from open flames.
3. Spray a marine-grade fabric protectant (such as 303 Fabric Guard) in a sweeping, overlapping pattern across the exterior surface.
4. Apply two light coats rather than one heavy coat, allowing the first coat to dry for 30 minutes before applying the second. Let the cover cure in direct sunlight for 2 to 4 hours before use.

Fabric-Specific Cleaning Parameters and Chemical Tolerances

The table below provides the precise cleaning parameters, chemical restrictions, and washing tolerances for the most common outdoor furniture cover fabrics.

Common Cover Cleaning Failures and Corrective Actions

Despite best intentions, cleaning outdoor covers can occasionally result in damage or persistent issues. Below are common failures and how to remedy them.

Scenario 1: The Inner Waterproof Backing is Flaking or Peeling

• Root Cause: The polyurethane or PVC backing has degraded due to age, UV exposure, high-heat dryer cycles, or exposure to harsh petroleum-based solvents.
• Actionable Fix: Mild flaking can be temporarily arrested. Thoroughly brush away all loose, peeling flakes from the interior. Spray the affected areas with a flexible, waterproof polyurethane sealant (such as Gear Aid Seam Grip or a flexible rubberized coating spray) to seal the exposed fabric fibers. If more than 30% of the backing is peeling, replace the cover to protect your furniture.

Scenario 2: Persistent Black Mildew Stains Remain After Washing

• Root Cause: The mold spores have penetrated deep into the fabric weave, or the cleaning solution lacked the chemical strength to break down the organic pigmentation.
• Actionable Fix: For bleach-safe acrylics, increase the bleach concentration to 1.5 cups per gallon of water and add 1/4 cup of baking soda to create a paste. Apply the paste directly to the black spots, let it sit for 30 minutes under plastic wrap (to keep it wet), scrub with a soft-bristle brush, and rinse. For polyester covers, apply a 3% hydrogen peroxide solution directly to the spots, let it bubble for 10 minutes, scrub, and rinse thoroughly.

Scenario 3: The Cover Shrinks and No Longer Fits the Furniture

• Root Cause: Exposure to hot water (above 100°F/38°C) during washing, or exposure to mechanical heat inside a tumble dryer.
• Actionable Fix: Synthetic polyester and vinyl cannot be un-shrunk once thermal deformation occurs. For cotton canvas or high-end acrylic covers, soak the cover in a tub of lukewarm water mixed with 1/2 cup of hair conditioner for 30 minutes. This relaxes the natural and synthetic fibers. Gently stretch the cover back over your furniture frame while it is damp, allowing it to air-dry directly on the structure to regain its original shape.

Frequently Asked Questions

Can you put outdoor furniture covers in the washing machine?

You should only machine-wash outdoor furniture covers if they are made of 100% solution-dyed acrylic without any polyurethane or vinyl backing. Use a commercial front-loading washing machine on a delicate cycle with cold water and mild detergent. Never use a top-loading machine with a center agitator, as the mechanical motion will tear the heavy fabric and destroy the seams.

How do you get green algae off outdoor furniture covers?

To remove green algae, spray the affected areas with a solution of 1 part distilled white vinegar and 1 part water, or a commercial outdoor cleaner designed for fabrics. Allow the solution to dwell for 15 to 20 minutes to break down the cell walls of the algae, then scrub gently with a soft-bristle brush and rinse thoroughly with a garden hose.

How often should outdoor furniture covers be cleaned?

Outdoor furniture covers should undergo a light rinsing once a month to remove surface dust, pollen, and organic debris before they can embed in the fabric. A deep, soapy scrub and mold-remediation process should be performed twice a year: once in the spring before regular patio use, and once in the autumn before storing your furniture for the winter.

Can you use bleach on outdoor furniture covers?

Bleach is safe to use only on solution-dyed acrylic fabrics (such as Sunbrella) for mold and mildew remediation. Never use bleach on polyester covers, canvas covers with wax treatments, or any cover featuring a polyurethane or vinyl waterproof backing, as the chlorine will degrade the polymers and cause the backing to crack and peel.

Protect and Preserve Your Outdoor Spaces

Invest in the longevity of your outdoor living area by keeping your protective fabrics clean and fully waterproofed. Explore our premium selection of professional-grade fabric cleaners and UV-blocking protectants to defend your outdoor investments against the elements all year round.