Tyre puncture repair

One important factor established by British standard BSAU159 is the location of the puncture. The technical regulation advises that only punctures located in the T area of the tyre should be repaired, which is the central part of the tread. Whereas if the puncture is located too close to the tyre’s sidewall, it should not be repaired because it may not be safe and may not last long.

The T area is the area between 60% and 70% of the tyre’s nominal width. This area is therefore different on each tyre model as it depends on the overall dimensions. Plus, punctures in the T area that can be repaired must have a maximum diameter of 6mm, established by a professional after a careful inspection of the damaged tyre.

As such, tyre punctures can only be repaired if the hole is away from the sidewalls and in the central part of the tyre. The hole must also be small for the repair to be effective and safe, ensuring a high-quality end result.

Tyres must have the right pressure to meet the appropriate safety standards. In order to repair a puncture, you may need to partially inflate the tyre to identify the exact place where the damage or tear has occurred. In this case, you should never exceed a tyre pressure of 15psi and gradually inflate the tyre in small increments of 5psi. This must be done using the appropriate tools and you may have to go to a specialist centre where they can do this professionally and safely.

After repairing the puncture, it is essential to check the pressure and ensure that the value is the same as the tyre pressure recommended by the manufacturer. Generally, tyres should be inflated to between 28 and 36psi, while a drop of more than 25% indicates that the tyre is damaged or needs to be inflated.

RUN FLAT tyres are specific models that have reinforced sidewalls. This allows you to continue driving in the event of a puncture at a low speed and for a certain number of miles. In general, you can drive up to 50 miles at a maximum speed of 50mph with a punctured RUN FLAT tyre.

A vehicle with RUN FLAT tyres has a big advantage over traditional tyres. After a puncture, you do not need to stop straight away to replace the tyre. You can keep driving to the nearest service centre where they can assess the damage.

Manufacturers advise against repairing RUN FLAT tyres because of the reinforced structure. In fact, the tyre’s high level of resistance could make it hard to spot minor secondary damage, so there is a risk of only detecting the main damage and not effectively repairing the tyre.

Generally speaking, punctured RUN FLAT tyres should not be repaired but replaced, but it all depends on the individual case. In these circumstances, you should go to a service centre and have the tyre checked by a qualified professional. The technician will tell you what the best option is, and it is not advisable to fix the tyre yourself.

According to British standard BSAU159, in some cases you should not try to repair the tyres but replace them instead. In particular, you should avoid repairing a tyre puncture when:

• the tread depth is low (the legal minimum is 1.6mm);
• the tyre casing is broken or damaged;
• the punctured tyre also has cuts, splits or cracks that reach the carcass;
• the tyre coating looks worn;
• the tyre has been contaminated by chemical agents like solvents;
• excessive tread wear or rubbing of the sidewall have caused the cords to become exposed;
• the tyre has secondary damage in addition to the puncture, caused by insufficient inflation, for example;
• the tyre has become separated from the tread or sidewall, or the belt is sticking out of the structure;
• the tyre has already been repaired but not properly.

A tyre puncture should not be underestimated as it can compromise road safety and increase the risk of accidents. If you have a tyre puncture, do not take any risks: head straight to your nearest tyre dealer to have them checked and ask a professional for advice.