The best patio furniture covers

The mistake nearly everyone makes

A patio furniture cover has two jobs, and most buyers only know about one of them. It has to keep rain out, and it has to let moisture escape.

Skip the second and you have built a humidity chamber. Furniture covered while even slightly damp, under a fully sealed unvented cover, spends the winter in warm still air at high humidity — which is close to ideal mildew conditions. What comes out in spring is mildewed cushions, a musty frame and, on steel, active corrosion under the paint. That is worse than leaving the furniture open to the wind.

What actually matters in a cover

Why fabric weight is only moderate

600D and 800D numbers get quoted heavily in listings because they are easy to compare. In practice a heavier fabric mainly resists abrasion at corners and tearing in wind — real benefits, but secondary to whether the cover vents and whether it stays on. A vented 300D cover that is strapped down beats an unvented 800D one that blows off.

Fit and sizing

Covers are sold by dimensions, and getting it wrong in either direction causes problems.

• Too loose: the cover flaps in wind, which abrades the furniture underneath at every contact point and wears through the cover itself at the corners.
• Too tight: corners take all the strain and split, and the cover pulls flat across the top so water pools instead of running off.
• Measure the furniture, not the space. Width, depth and height at the tallest point, with chairs pushed in if you are covering a dining set as one unit.
• Some slope is good. A cover with a bit of structure — or furniture arranged so the cover sits higher in the middle — sheds water. A flat top pools it, and a pool freezes and stretches the fabric.

Using a cover correctly

1. Dry the furniture first. Non-negotiable. If you cover wet furniture, the cover holds the moisture against it.
2. Clean it first, at least once a year. Covering over algae film and leaf litter seals organic matter against the surface for months. Our cleaning guide has the sequence by material.
3. Bring cushions indoors rather than covering them. A cover is not storage for cushions — foam under a cover for four months is exactly the mildew scenario above. Use a deck box if indoor space is short.
4. Strap it down. Every time. An unstrapped cover in a storm is a sail.
5. Get the feet off standing water. A cover does nothing about the water underneath the furniture, and that is where steel feet and wooden end grain fail.
6. Check it mid-winter. Five minutes to make sure it has not blown partially off or collected a pool of ice.

Whether covering is worth doing at all depends on what the furniture is made of — an HDPE set genuinely does not need it, while a steel-framed one benefits enormously. Our covers explainer works through that material by material.