Puncture Repair vs Tyre Replacement: When Can a Tyre Be Fixed?

Discovering a nail, screw, or sharp object in your tyre is an annoying but common part of driving. The good news is that not every puncture means you need to buy a new tyre. The bad news is that not every puncture can be safely repaired either. Here is how to tell the difference.

The British Standard: BS AU 159

In the UK, tyre repairs must comply with British Standard BS AU 159. This sets out strict rules about where and how a tyre can be repaired, and is designed to ensure that repaired tyres are safe to use at motorway speeds. Any reputable tyre technician will follow this standard — and refuse to repair a tyre that does not meet the criteria.

The Repairable Zone

Not all of the tyre surface is eligible for repair. According to BS AU 159, only the central three-quarters of the tread area (sometimes called the minor repair area) can be repaired. This means:

• Punctures in the centre of the tread — generally repairable, provided other conditions are met
• Punctures near the shoulder (where the tread meets the sidewall) — cannot be safely repaired
• Sidewall damage — never repairable. The sidewall flexes constantly while driving, and a repair would fail under the stress

When Can a Tyre Be Repaired?

A puncture repair is typically possible when:

• The damage is in the central tread area
• The puncture is no larger than 6mm in diameter
• There is only one puncture (or existing repairs are well separated from each other)
• The tyre has not been driven on while flat — driving on a deflated tyre can cause internal damage that is invisible from the outside
• The remaining tread depth is above the legal minimum of 1.6mm
• The tyre is not excessively aged or deteriorated

When Must a Tyre Be Replaced?

A tyre must be replaced rather than repaired when:

• The damage is in the sidewall or shoulder area
• The puncture hole is larger than 6mm
• The tyre has been driven on whilst flat, potentially causing hidden internal damage
• There are multiple punctures close together
• The tyre shows signs of bulging, cracking, or cord exposure
• The tread depth is already at or near 1.6mm
• A previous repair has failed

What About a Nail Still Stuck in the Tyre?

If you spot a nail or screw embedded in your tyre and it is still holding air, leave it in place. It is acting as a plug and removing it will cause the tyre to deflate. Drive carefully (avoiding high speeds) to a safe location and call for professional help.

The technician will remove the tyre from the wheel, inspect the interior for hidden damage, and then perform a proper combination repair (patch and plug) from the inside — if the tyre meets the repair criteria.

Why Plug-Only Repairs Are Not Safe

You might have seen tyre repair kits that push a rubber plug into the puncture from the outside. While these can be a useful temporary measure to get you home, they are not considered a permanent repair under BS AU 159. A proper repair requires the tyre to be removed from the rim, the interior inspected for damage, and a combination patch-plug applied from the inside.

Getting It Right

At NN Mobile Tyres, every puncture is assessed on-site following BS AU 159 guidelines. If a repair is safe and appropriate, we carry it out at your location across Oxfordshire. If the tyre needs replacing, we carry a wide range of sizes in our van to get you back on the road quickly.

Frequently Asked Questions

How long does a puncture repair last?

When carried out correctly to BS AU 159, a combination repair is designed to last the remaining life of the tyre. It is a permanent fix that is safe for motorway driving.

Can I get a puncture repaired if my tyre is already low on tread?

If the remaining tread depth is close to or below the legal minimum of 1.6mm, most technicians will recommend replacement rather than repair. There is little point repairing a tyre that will need replacing soon anyway.

Is it safe to drive with a slow puncture?

A slow puncture should be dealt with as soon as possible. While you may be able to top up the pressure and drive short distances, the cause needs to be identified and properly repaired or the tyre replaced. Ignoring a slow puncture risks a sudden deflation at speed.

Need help? Call NN Mobile Tyres on 07362 638978 or WhatsApp us — we are available 24/7 across Oxfordshire.