A dirty car cover stops working. That is the practical reason to wash it, and it is worth understanding the mechanism before the method.
As dirt, grease and dust build up in the fabric, two things happen. First, those contaminants transfer onto your paint and glass, leaving the windshield muddied and the finish foggy. Second, and more damaging, the buildup causes wicking: the impurities draw water through the fabric by capillary action, defeating whatever water resistance the material had. A cover that beaded rain when new will start passing it straight through to the paint once it is loaded with grime.
Cleaning your cover keeps your vehicle cleaner and materially extends the cover's life. Below are the official instructions, including the fabric chart that tells you exactly which cleaner, machine and drying method applies to your grade.
- Fabric Chart: Settings by Grade
- How Often to Wash
- Washing by Hand (Recommended)
- Washing in a Machine
- Drying, by Grade
- Spot Cleaning Specific Stains
- What Never to Do
- Restoring Water Repellency
- RV, Hearse, Limousine and Bubble Covers
- Storing It After Washing
- Frequently Asked Questions
Fabric Chart: Settings by Grade
Find your grade and use these settings. The abbreviations are explained directly below the chart.
| Grade | Machine type | Cleaner | Water temp | Machine dry | Air dry |
|---|---|---|---|---|---|
| Supreme Shield HD | C | SG | Cold | No | Yes |
| Gold Shield 5L | C | SG | Cold | No | Yes |
| Black Satin BL | H or C | PD or SG | Cold | Yes, medium | No |
| Silver Shield 3L | C | SG | Cold | No | Yes |
| Bronze Shield 2L | C | SG | Cold | No | Yes |
Machine type
- H: large home-sized top or front load, with or without an agitator.
- C: commercial machine, or a large home front-loader, with no agitator.
Note that only Black Satin BL may go in an H machine. Every other grade requires an agitator-free machine, because an agitator post twists and abrades multi-layer fabric and can separate the bonded layers.
Cleaner
- SG: Simple Green, diluted at one quarter cup per one cup of water.
- PD: mild powder detergent, dissolved in water first before it touches the fabric. No bleach, no fabric softener.
Undissolved powder sitting against fabric is abrasive and can leave residue that attracts dirt, which is why dissolving it first matters.
Water temperature
Cold, on every grade, without exception. Heat softens and can distort the water-resistant coating and the bonded layers.
Drying
Black Satin BL is the only grade that goes in a dryer, on medium. Every other grade air dries. Details in the drying section.
How Often to Wash
There is no fixed schedule, so judge it by condition and environment:
- Every two to three months for a cover in normal outdoor use.
- Monthly if you park under trees, near construction, on gravel, or in a heavy-pollen area.
- Once or twice a year for an indoor cover, which mostly collects dust.
- Immediately after bird droppings, tree sap or road tar land on it. Those are acidic or adhesive and get harder to remove the longer they sit.
- Before long-term storage, and it must be fully dry before it goes in the bag.
The quickest test for whether it is overdue: spray it with a hose. If water beads and rolls off, the fabric is still clean and the coating is intact. If it soaks in and darkens the fabric, the cover is either dirty, has lost its repellency, or both.
Washing by Hand (Recommended)
This is the method we recommend, for two reasons: no machine can abrade the fabric, and washing the cover while it is fitted on the vehicle gives you a taut surface to work on with no wrinkles or folds to trap detergent.
What you need
- All-purpose cleaner or mild detergent
- Water, warm or cold
- Bucket, hose and sponge
- Somewhere to hang it to dry
Steps
- Put the cover on your car, stretched tight to minimise wrinkles.
- Fill a bucket with water and add a mild detergent to make a cleaning solution.
- Spray the cover with the hose to loosen debris and residue such as dirt and bird droppings. Soak the sponge in the solution and scrub the cover.
- Rinse the cover thoroughly with the hose two or three times, until there is no trace of suds.
- Turn the cover inside out and put it back on the car.
- Repeat the cleaning steps so both faces are properly washed.
- Remove the cover and rinse it once more with the hose.
- Hang the cover to dry.
Washing the inside matters as much as the outside. The inner face is what touches your paint, so any grit embedded in it is exactly what causes fine scratching when you fit and remove the cover.
Washing in a Machine
Faster, and fine when you use the right machine for your grade. Check the chart above first: only Black Satin BL tolerates a home machine with an agitator.
What you need
- All-purpose cleaner or mild detergent
- A commercial front-loading washer, the type found in a laundromat
Steps
- Put the cover in the most spacious machine available. Extra-large covers, for vehicles such as SUVs and trucks, must always be washed in a commercial front-loader regardless of fabric type. A domestic drum cannot move that much fabric, so it packs into a mass, the detergent never rinses out, and the seams take the strain.
- Use the gentle cycle if the machine offers one.
- Refer to the fabric chart for the right cleaner and settings for your material. Never add fabric softener.
- Run two additional rinses with water only, to be certain all cleaning agent is out of the fabric.
- Dry it as the chart specifies for your grade.
Why the extra rinses matter: detergent left in the fabric attracts and holds moisture. A cover with residue in it will feel damp in humid weather and will wick water rather than shedding it, which is the opposite of what you just cleaned it for.
Drying, by Grade
Supreme Shield HD, Gold Shield 5L, Silver Shield 3L, Bronze Shield 2L
Air dry only. Hang the cover over a railing, a clothesline or the vehicle itself, in shade with air moving around it. Do not put these grades in a dryer: tumbling heat can delaminate the bonded layers and damage the micro-porous film that makes the fabric breathable.
Turn it once during drying so both faces get airflow, and make sure the hems and seams are dry, not just the panels. Those are the last parts to dry and the first places mildew starts.
Black Satin BL
Machine dry on medium. This is the one grade where a dryer is correct, and it helps the satin face settle back to its original finish. Do not use high heat, and never add dryer sheets, which leave a coating that attracts dust.
How long to allow
Give an air-dried cover several hours at minimum, and a full day in humid conditions. It has to be completely dry before it is folded or bagged. A damp cover in a closed bag grows mildew, and mildew permanently stains and weakens fabric. If you are unsure, leave it another few hours.
Spot Cleaning Specific Stains
For anything localised, treat the spot rather than washing the whole cover.
| Stain | Treatment | Note |
|---|---|---|
| Bird droppings | Soften with water, then mild detergent solution and a sponge | Acidic. Deal with it the same day in summer heat |
| Tree sap | Rubbing alcohol on a cloth, dab rather than rub, then rinse | Test on a hem first. Rinse fully, alcohol strips repellency |
| Road tar | Mild detergent and patience, repeated passes | Avoid solvents, they attack the coating |
| Mildew spots | Diluted Simple Green, scrub gently, rinse, dry fully in sun | Staining may be permanent. Prevention is the only real fix |
| Pollen | Hose off, no detergent needed | Do this often in spring, it is abrasive when dry |
| Road salt | Rinse thoroughly with plain water | Rinse the inner face too, salt migrates through |
| Grease or oil | Dab with detergent solution, rinse, repeat | Never a degreaser, it will strip the coating |
Always rinse the treated area thoroughly. Any cleaner left in the fabric becomes a dirt magnet and a wicking point.
What Never to Do
- Never use fabric softener. It coats fibres and destroys both breathability and water repellency. This is the single most common way people ruin a good cover.
- Never use bleach. It degrades the coating and weakens the fibres.
- Never use hot water. Cold on every grade.
- Never machine dry any grade except Black Satin BL, and that on medium.
- Never use an agitator machine except on Black Satin BL.
- Never use a pressure washer. It forces water through the fabric and can separate the bonded layers.
- Never dry clean. The solvents strip the water-resistant treatment.
- Never use dryer sheets. Same problem as fabric softener.
- Never iron or steam it. Heat distorts the coating.
- Never fold or store it damp. The cause of nearly every mildew complaint we see.
If mildew came from covering the car before it had dried, fix the habit as well as the cover: what really happens when you cover a wet car.
Restoring Water Repellency
Water repellency comes from a coating on the fabric, and coatings wear with UV exposure and folding. Washing removes the dirt that causes wicking, but it does not restore a coating that has genuinely worn away.
Test it after the cover is clean and dry: spray it with a hose. If water beads and rolls, you are done. If it soaks in even though the fabric is clean, the repellency has degraded and a spray-on DWR treatment made for outdoor fabrics will restore most of it. Apply it to a clean, dry cover, cover the whole surface evenly, and let it cure per the product instructions before use.
For how long a cover should last before this becomes routine, see how long do car covers last.
RV, Hearse, Limousine and Bubble Covers
RV and trailer covers
Same fabric family and the same rules on cleaner and temperature, but they are far too large for any machine, commercial included. Hand wash them fitted on the RV, exactly as described above, working in sections with a soft brush on an extension pole for the roof. Air dry only.
Hearse and limousine covers
Follow the chart for the grade you own, and use a commercial front-loader given the size. Hand washing on the vehicle is easier and gentler for these.
Indoor Inflatable Bubble
Not a fabric cover, so none of the chart applies. Wipe the clear panels down with mild soap and water and a soft cloth, then dry them. Never machine wash it, and never use solvents or abrasive cleaners on the PVC, which will cloud it permanently. Keep the fan filter clean, since that is what keeps the air inside dry.
Storing It After Washing
- Confirm it is completely dry, hems and seams included.
- Fold it rather than stuffing it. Repeated random creasing is where the coating cracks first.
- Vary the fold lines slightly between storings so the same creases are not always stressed.
- Use the storage bag it came with, and keep it somewhere dry and out of direct sun.
- Do not store it in a car trunk in summer. Sustained heat is hard on the coating.
Technique for a cover that goes on and off often: how to fold and store a car cover like a pro.
Frequently Asked Questions
How do I wash a car cover?
Hand washing is recommended. Fit the cover on the car stretched tight, hose it to loosen debris, scrub with a sponge and mild detergent solution, rinse two or three times until no suds remain, then turn it inside out, refit it and repeat so both faces are cleaned. Rinse once more and hang it to dry. Machine washing is fine in a commercial front-loader on gentle with cold water, followed by two water-only rinses.
Can I wash a car cover in a home washing machine?
Only Black Satin BL may be washed in a large home machine with or without an agitator. Supreme Shield HD, Gold Shield 5L, Silver Shield 3L and Bronze Shield 2L all require a commercial machine or a large home front-loader with no agitator, and extra-large covers for SUVs and trucks must always go in a commercial front-loader regardless of fabric.
What detergent should I use on a car cover?
Simple Green diluted at one quarter cup per cup of water works on every grade. Black Satin BL can also take a mild powder detergent, dissolved in water first. Never use bleach and never use fabric softener, which coats the fibres and destroys both breathability and water repellency.
Can I put a car cover in the dryer?
Only Black Satin BL, on medium heat. Supreme Shield HD, Gold Shield 5L, Silver Shield 3L and Bronze Shield 2L must be air dried, because tumbling heat can delaminate the bonded layers and damage the micro-porous film that makes them breathable.
What water temperature should I use?
Cold, on every grade without exception. Warm or hot water can soften and distort the water-resistant coating and the bonded layers.
How often should I clean my car cover?
Every two to three months in normal outdoor use, monthly if you park under trees or in a dusty area, and once or twice a year for an indoor cover. Spot clean bird droppings and sap immediately. A quick test: hose the cover, and if water soaks in instead of beading, it is due.
Why does my cover leak now when it used to shed water?
Usually wicking. Dirt, grease and dust in the fabric draw water through by capillary action, defeating the water resistance. Washing the cover normally restores it. If water still soaks in when the cover is clean and dry, the repellent coating has worn and a spray-on DWR treatment will restore most of it.
Can I pressure wash a car cover?
No. A pressure washer forces water through the fabric and can separate the bonded layers. Use a normal garden hose.
How do I get mildew out of a car cover?
Scrub the affected area gently with diluted Simple Green, rinse thoroughly and dry it completely in sunlight. The staining may not come out entirely, since mildew discolours fibres permanently. Prevention is the real answer: never fold or bag a cover that is not bone dry.
How do I wash an RV cover?
By hand, fitted on the RV. RV covers are too large for any machine, including commercial ones. Work in sections with a soft brush on an extension pole, use diluted Simple Green and cold water, rinse thoroughly, and air dry only.
Should I wash the inside of the cover too?
Yes, and it matters more than the outside. The inner face touches your paint every time you fit and remove the cover, so grit embedded there is what causes fine scratching. The hand-wash method turns the cover inside out specifically so both faces get cleaned.
Keeping it working
A clean, dry, properly stored cover will protect a vehicle for years. If yours is past saving, find a replacement patterned for your exact year, make, model and trim on our car covers page, backed by our warranty. Replacement storage bags and patch kits are available separately.