What is a flat tyre?

A flat tyre refers to a tyre that has lost its air, resulting in deflation. It’s a common issue for all vehicles with pneumatic tyres, including cars and bikes.

The causes of a flat tyre can be various. A sharp nail or glass shard could penetrate the tyre, or there may be damage due to hitting a pothole - a common problem on today’s roads. Other causes include a leaky valve stem, a faulty seal between the tyre and the wheel rim - known as the bead, or general wear and tear.

Checking your tyres should be part of your regular car maintenance schedule, as they must meet certain standards to be road legal. This includes having a tread of no less than 1.6mm and being free of splits and bulges.

Let’s get into a bit more detail 👇

Can you drive on a flat tyre?

Driving on a flat tyre is neither safe nor legal.

From a safety perspective, driving on a flat tyre compromises your car's handling and braking ability, potentially leading to accidents. It can also damage the wheel rims and vehicle suspension.

Legally, the UK Highway Code stipulates that vehicles must be roadworthy, and this includes having tyres that are in good condition. According to the Road Vehicles (Construction and Use) Regulations 1986, it's illegal to drive a vehicle that's in a dangerous state, and that includes one with flat tyres.

If caught, you could face a fine, points on your licence and, in serious cases, be disqualified from driving. If you were involved in an accident and were driving on a flat tyre, your insurance company could refuse to cover the claim.

How to temporarily repair a flat tyre

It’s a good idea to have a puncture repair kit containing sealant and a compressor in your vehicle. While it’s only a temporary solution, sealant typically lasts between 50 and 100 miles, enabling you to get to the nearest garage.

Before you start:

• Find a safe place to stop
• Switch off your engine
• Turn on your hazard lights
• Put the handbrake on, or, if automatic, put the vehicle in ‘P’
• Make sure all your passengers are away from the car, in a safe place
• Read the instructions on the repair kit before you start
• Examine the tyre to find the puncture.

If the hole is bigger than 4mm, the wheel rim is damaged, or the puncture is on the wall of the tyre, a repair kit won’t fix the issue. You also shouldn’t remove any large pieces of glass or nails that have pierced the tyre, as this can enlarge the hole.

Once the puncture is located, carefully drive forward or back until it is at the top of the tyre. Remember to put the handbrake or parking brake back on. Then insert the sealant and re-inflate the tyre with the compressor, and follow the kit’s instructions:

• Insert the sealant into the tyre through the air valve
• Connect the compressor. This may connect to the tyre valve directly or to the bottle of sealant to help pump the sealant into the tyre
• Plug the compressor into your car’s 12v socket
• Check your vehicle manual to find the correct tyre pressure
• Turn on the engine and switch on the compressor
• Turn the compressor off and detach it once the tyre is at the correct pressure
• Drive and check the tyre

Many sealant kits need you to drive a little way for the sealant to spread around the tyre. The kit will explain if you need to do this.

Remember to get to a garage as soon as you can.

How to change a tyre

While carrying a spare tyre in your car is not legally required, it could get you out of a challenging situation. If your spare is a saver tyre - smaller than regular tyres - it's not meant for long distances or high speeds. Visit a tyre professional to replace the temporary spare with a regular tyre as soon as possible.

Here’s a quick step-by-step guide to changing your tyre:

• Park your vehicle on level ground, away from traffic
• Turn on your hazard lights and apply the parking brake
• Gather your tools - a jack, lug wrench, and your spare tyre
• Using your lug wrench, loosen the lug nuts on the tyre that needs to be replaced
• Don't fully remove the nuts yet - just break the resistance
• Place the jack under the vehicle using your car's manual for specific locations where the jack should be placed. Then, start to lift your car off the ground
• Once the vehicle is raised, remove the lug nuts completely. After the nuts are off, pull the tyre straight toward you to remove
• Place the spare tyre on the hub, aligning the rim with the lug bolts. Push the spare all the way onto the vehicle hub as far as it will go
• Put the lug nuts back on, but don't tighten them completely yet
• Lower the vehicle from the jack until it's no longer supporting the weight of the vehicle, but is not fully on the ground
• Tighten the lug nuts as much as possible. It's best to work in a crisscross pattern, tightening opposite nuts
• Lower the vehicle completely
• Make sure the lug nuts are tight. Then, check the tyre's air pressure to ensure it's safe to drive on

What are run-flat tyres?

Run-flat tyres are designed to still function for a limited distance after they have been punctured or lost pressure, thanks to reinforced sidewalls. This allows you to continue driving for a short distance, usually around 50 miles, at a speed of less than 50mph, to reach a safe location or repair shop.

It's important to note that while run-flat tyres offer convenience and additional safety in certain situations, they have some drawbacks.

They generally offer a less comfortable ride than traditional tyres and can be more expensive to replace - typically up to 50% more. Also, once a run-flat tyre has been punctured, it often needs to be replaced rather than repaired.

Run-flat tyres are often put on new vehicles equipped with a Tyre Pressure Monitoring System (TPMS). This system is designed to detect a puncture in a run-flat tyre and subsequently generate an alert on your vehicle's dashboard. To maintain this system's accuracy, run-flat tyres must be fitted on all wheels.

Calling roadside assistance

You never know when you might need roadside assistance, so you should always have the phone number and any membership details to hand.

If you're in immediate danger - for instance, if your car has broken down in the middle of a highway and it's unsafe to exit the vehicle, call emergency services immediately.

Roadside assistance can help with vehicle issues, but your safety is the highest priority.

Flat tyres and car insurance

The inclusion of flat tyre repairs or replacements in car insurance policies depends on the specifics of your policy and the insurance provider.

If your policy includes roadside assistance or if you've added it as an extra, it may cover the cost of repairing or replacing your tyres, or some providers offer tyre-specific cover.

Ensure you understand your policy excess because even if a repair or replacement is covered, you'll likely be responsible for paying the excess.

This could be more than you’d spend on a new tyre, making it not cost-effective to claim for tyres on your insurance.

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