Covering a car for winter: choosing, fitting and living with a car cover

For a car laid up in a dry garage, a cover is generally worth having. An indoor cover is there mainly to keep dust off and to protect the paint from small knocks and scuffs: tools, bicycles, watch straps, zips and jeans rivets as people squeeze past in a crowded garage.

Outdoors the answer is less clear cut. A good outdoor cover keeps rain out of the cabin and stops leaves, tree sap and bird droppings settling on the paint and in the vents and drain channels. The trade-off is that a cover outside is fabric moving against paint, and it can hold moisture against the body. Classic & Sports Car notes that covers can chafe paint and work best in sheltered spots, and that even a breathable cover can keep paintwork damp for longer than an uncovered car takes to dry. Hagerty UK quotes a paint repairer who had seen lacquer damaged by covers left on too long.

A cover is not a dehumidifier

A cover keeps things off the car; it does nothing to dry the air around it. The underside of a covered car is still exposed to damp air, and condensation can form beneath a cover in bad weather, including a breathable one. If the garage itself is damp, deal with that first: see damp and condensation. A cover is one step in a wider winter lay-up, and it belongs near the end of the lay-up checklist, once the car is clean and dry.

• Indoor covers: light, breathable and easy to handle. A soft, fleecy inner face does the best job of protecting polished paint. They are not made to shed water, so they are no use outside.
• Outdoor covers: the better ones combine a soft lining against the paint, a breathable middle layer and a water-repellent outer face. Cover makers describe these as suitable for year-round use in normal UK winter weather.
• Lighter outdoor covers: showerproof covers are meant for short spells, such as a day at a show or a car under a carport, rather than a whole winter in the open.
• Read the description carefully: "waterproof" does not mean "breathable". Basic waterproof covers often trap moisture underneath, which is the opposite of what a stored car needs.

Air carries water vapour. When the car's metal and glass are colder than the air around them, typically after a cold night followed by a quick warm-up, that vapour condenses on the cold surfaces. A stored car has no engine warmth to dry it off, so moisture lingers.

A cover that does not let the car breathe traps that water against the paint and inside the cabin. Hagerty UK warns that this can advance corrosion and cause lacquer to lift; Footman James notes that non-breathable fabrics and plastic tarpaulins can trap moisture and damage paint. Inside, the results can include mould, mildew and musty smells.

A breathable cover lets vapour escape, but slowly. Cover makers point out that some condensation under a breathable cover in bad weather is normal, and a soft fleecy lining can itself become wet. Breathability reduces the problem; it does not remove the need to check the car.

Fit affects airflow too. Cover specialists quoted by Classics World suggest a cover outdoors should fit more like a mitten than a glove, so that air can circulate, and at least one cover maker tells owners to tension the underbody straps without pulling them tight for the same reason.

• Universal covers: cheaper and sized to suit a range of cars. They can work if they fit snugly and have secure straps, but a loose universal cover outdoors is the most likely to flap.
• Tailored covers: cut for a specific model, with pockets for the door mirrors and allowance for spoilers, bumpers and other features. Outdoors, a tailored cover is less likely to move and damage the paint.
• Mirror pockets: a feature of most tailored covers, and usually the first part to fit, which helps line the cover up.
• Elasticated hems: an elastic hem front and rear pulls the cover under the bumpers and keeps it close to the body.
• Underbody straps: straps passing under the car stop the cover billowing in the wind. Some makers also offer extra over-body storm straps.
• Snug, not tight: a loose cover flaps and abrades the paint; a cover that is too tight strains its seams and can mark the paint too. Aim for a cover that sits close without being stretched.

Dirt trapped between fabric and paint is a common cause of scratching, so care at the fitting and removing stages matters.

1. Start with a clean, dry, cool car. Wash and dry it thoroughly, and let the engine and exhaust cool. Never cover a wet or salty car.
2. Check fresh paint first. If the car has been resprayed recently, ask the painter or the cover maker before covering it.
3. Retract or remove the aerial. Otherwise it can damage the cover.
4. Lay out the underbody straps before parking, if the design allows, so they do not have to be pushed underneath afterwards.
5. Find the front. Most covers have a label stitched into the front hem.
6. Place the cover on the roof and unfold it along the length towards each end, rather than pulling it across the car from one side.
7. Fit the mirror pockets early, then draw the elastic hems over the front and rear.
8. Fasten and tension the straps, keeping them snug rather than tight.

To remove the cover, release the straps and hems first, then lift the cover clear and fold it as it comes off. Do not drag it across the paint.

A car living outside through a Ryedale winter needs more attention than one in a garage. A cover helps, provided someone keeps an eye on it.

• Check weekly. Cover makers advise checking both car and cover every week during a prolonged spell of damp, snow or wet weather.
• Lift it on dry days. When the weather allows, take the cover off, open the car up and let the cover and the car air. If the lining is wet through, dry it before refitting.
• Watch the wind. A cover can be partly lifted in a severe storm, and at least one maker excludes storm damage and use above a stated wind speed from its warranty. Check the cover after every gale and re-tension the straps.
• Inside the car: look for damp carpets, mould and musty smells at each check; these mean moisture is being trapped. The long-term storage page covers keeping a laid-up car healthy over longer periods.

An outdoor cover is itself worth stealing. Many have eyelets on each side so that a cable lock can be passed under the car and locked, and some come with their own anti-theft fastening.

Where the car is kept is a matter for your insurer. Insurers take overnight location into account when setting premiums, and you should tell them truthfully where the car is normally kept and update the policy if that changes. Covering a car does not change where it is kept, so a car moved from a garage to a driveway for the winter still needs that change reported.

• Airflow enclosures ("car bubbles"): a sealed fabric enclosure with fans that circulate treated or filtered air around the car. They need power all the time to work. See our owner's guide to the Carcoon.
• Carports: keep rain and snow off and protect the paint from droppings, but must be firmly anchored to the ground. A carport does not enclose the car, so a cover may still be worth using underneath.
• Portable garages: a tent-like frame with a fabric cover. They need a sizeable space and must be anchored, with pegs or with weights where the ground will not take pegs.

• Follow the label. Some covers are machine washable at 30°C; others are hand wash only with a mild washing liquid.
• Wash outdoor covers on the car. Several makers suggest hosing the cover down while fitted, sponging it gently with mild car shampoo, rinsing and letting it air dry.
• Dry it completely. Line or air dry the cover, and never pack it away damp.
• Store it in its bag in a dry place, ready for next time.

• Plastic sheeting or tarpaulin: neither lets the car breathe, and both encourage condensation, mould and mildew.
• Covering a wet, dirty or salty car: water and grit end up trapped against the paint.
• A waterproof but non-breathable cover used for a whole winter outdoors.
• A loose cover outdoors that flaps and scuffs the paint, or straps pulled so tight they stop air moving.
• Leaving the aerial up and tearing the cover.
• Fit and forget: never lifting the cover to check for damp underneath.
• Expecting the cover to cure a damp garage.
• Dragging the cover across the paint, or packing it away wet.

Mice and rats are a separate winter problem; see mice and rats. For the wider picture, return to the classic car storage hub.