Watch: Which home-made masks are most effective

Face coverings must be worn in shops and supermarkets in England starting today.

But if you are making your own, how do you know if it will be effective?

Home-made face coverings need to be at least two layers and preferably three to curb the spread of Covid-19, new research suggests.

Experts found one layer of cotton T-shirt material is fairly effective as a barrier against droplets expelled during speaking, but two are “significantly better at reducing the droplet spread caused by coughing and sneezing”.

Three layers would be even better, the researchers said, and their study found surgical disposable masks offer the best protection of all.

And while it is mandatory for the public to wear masks in shops, police in the borough have said they will not be patrolling the aisles.

Det Ch Supt Stephen Clayman, commander for Havering, Redbridge and Barking and Dagenham, said shops will take some responsibility for ensuring customers wear masks but said police are only likely to get involved if someone is “playing up and is aggressive towards shop staff because they won’t wear their mask”.