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BBQ cover condensation and rust

Updated: 22 October 2026

You put a waterproof cover on the barbecue, and later the burners show rust or the lid smells of mould. That can happen when the cloth has done the job it was sold for. A waterproof cover can still rust a barbecue because moist air stays underneath. Rain resistance and a dry cavity are different jobs. If the barbecue stays outside, cover it only when it is cool and dry, and lift the cover after wet weather. None of the twelve covers in the [barbecue cover comparison](/hub/grill-accessories/barbecue-cover) should be described as vented. Peter F. checked those listings for a vent. A qualifying purchase through our links can earn a commission at no extra cost to you.

You put a waterproof cover on the barbecue, and later the burners show rust or the lid smells of mould. That can happen when the cloth has done the job it was sold for.

Our top picks

GrillTough GrillTough, 147 cm

Best overall

GrillTough GrillTough, 147 cm
8.6/10about £34.99
View offer
Grillman Grillman, 132 cm

Rank 2

Grillman Grillman, 132 cm
8.5/10about £32.99
View offer
Kauytt Kauytt, 145 cm

Best value

Kauytt Kauytt, 145 cm
8.4/10about £9.99
View offer
On this page
  1. 1.Why the inside still gets wet
  2. 2.What these covers do not claim
  3. 3.Winter outside or a dry shed
  4. 4.When rust is on the fuel side

Why the inside still gets wet

Outback’s own note on a vented cover says a strong waterproof barrier can still trap moisture. The maker still tells you to take the cover off sometimes and to refit it only on a dry barbecue. World of BBQs says to remove the cover on a dry day after a long spell of rain and dry the inside. Leftover fat is where mould can grow. Daytime rain wets the patio and the air. Night-time cooling drops moisture onto steel under the cloth. A sealed hem keeps that damp in. The cover can bead rain on the outside and still leave the bowl wet. Wipe the fat off, let the steel dry, then cover it. After the next wet week, lift the cover again. A £35 vinyl cover can still trap damp if it stays sealed for months. Weight and a coating stop rain coming through the cloth. They do not empty the air that was already moist when you pulled the hem tight.

What these covers do not claim

Read the twelve listings for a baffled vent and you will not find one. GrillTough is polyester with a vinyl coating. Grillman puts polyvinyl chloride on the material field and weighs 1.83 kg. Ezilif, RICHIE, and KHAMAL print 420D. Kauytt and both BEEWAY lengths print 210D. YOTOM and Flintronic say Oxford and print no denier. None of those lines is an air vent. A sealed heavy sheet can still hold moist air. Kauytt at 470 g is 210D, and reviews call it thin. Thin cloth can wet through sooner, which is a different fault from trapped air. An AeroCover sold elsewhere at about £59.99 is a vented retail cover outside this set. Even Outback says a vent does not replace taking the cover off. If the old cover tore, use the BBQ cover buying guide for shape, size, fastening, and weight. If the steel rusted under a cover that never leaked, change the airing habit before you change the ASIN.
GrillTough GrillTough, 147 cm

Testsieger

GrillTough GrillTough, 147 cm
8.6/10about £34.99
View offer

Winter outside or a dry shed

World of BBQs’ winter article splits the storage in two. Outside, clean the barbecue, dry it, fit the cover, and lift the cover after wet weather so the inside can dry. Indoors, do not leave a cover on. Condensation in a shed or garage can harm burners, valves, and wood. Ideal Home’s storage piece makes the same first move: clean and dry, and use a shed or garage if you can move the barbecue. A cover bag, where the listing includes one, is for the cloth in the shed. A garage feels dry, and a covered barbecue in the corner still holds the moisture it brought in from the patio. Take the cover off once the barbecue lives under a roof.

When rust is on the fuel side

Stop cooking, and stop shopping for another cover, when the rust reaches a burner, a valve, or the hose. If you smell gas, or a cover would have to be cut around pipework, use the maker’s manual or a person who is competent on gas. A textile shell will not repair a leak. Which listing is the top pick, and why that badge is not a dryness test, is on best BBQ cover UK.

Common questions

Should you dry the barbecue before the cover goes back on?
Yes. Wipe grease off, let the steel dry, and only then pull the cover on. GrillTough also says to let the grill cool completely, because a hot lid can melt cloth. After a wet week, lift the cover on a dry day and dry what you find underneath. Putting the sheet back over a wet bowl seals the next round of condensation in.
What changes if the barbecue is in a shed?
Take the cover off. World of BBQs says an indoor cover can leave condensation on burners, valves, and wood. A garage is still indoors for this purpose. Use a storage bag, where the listing includes one, for the cover itself.
Do these covers have air vents?
No listing in this set clearly states a baffled vent. The pages name coatings and denier: vinyl, PVC, PU, 420D, 210D, or plain Oxford. GrillTough’s care line is about cooling and hosing the cover, not about a vent. Outback’s vented cover and a retail AeroCover are different products, outside these twelve ASINs.
Can leftover fat grow mould under a cover?
Yes. World of BBQs says mould can grow on leftover fat, which is why they tell you to clean before you cover. Wipe the fat off and let the surface dry before the cloth goes on. GrillTough’s bullets say to hose the cover and air dry it.
When is rust a reason to stop cooking, not a reason to buy another cover?
When it reaches a burner, a valve, or the hose, or when you smell gas. A new cover will not repair a corroded jet or a perished hose. Follow the maker’s manual, or ask someone competent on gas, if the damage is on the fuel side.

Related pages

How to measure a BBQ for a cover

Barbecue cover

Best BBQ cover UK: listing score, not a weather test

BBQ cover buying guide: shape, size, then the cloth

Round BBQ cover or a rectangular gas trolley cover

Sources

Public UK sources from the research digest. Shelf prices, stars, sizes, and review counts are the amazon.co.uk figures captured on 19 October 2026. Weber and AeroCover prices outside this set are from the pages named below, not from this table.

  1. Consumer Rights Act 2015, section 9 (retrieved 19 October 2026)
  2. The Cover Company: gas barbecue cover measuring allowances (retrieved 19 October 2026)
  3. World of BBQs: weatherproof, not waterproof (retrieved 19 October 2026)
  4. World of BBQs: storing a barbecue in winter (retrieved 19 October 2026)
  5. Outback: vented barbecue cover and trapped moisture (retrieved 19 October 2026)
  6. Weber UK: 57 cm charcoal cover (retrieved 20 October 2026)
  7. amazon.co.uk Best Sellers: Barbecue Covers (retrieved 20 October 2026)
  8. Ideal Home: how to store a barbecue (retrieved 19 October 2026)