What Is a Tyre Puncture?
A tyre puncture, better known as a flat tyre, is a condition in which a pneumatic radial deflates causing the wheel's rim to ride on the ground or the tread of the tyre. This could potentially lead to loss of vehicle control or permanent tyre damage.
In case of a flat tyre, you must gradually slow down and come to a standstill on one side of the road. If you continue to drive, you might end up damaging the wheel or be responsible for a deadly accident, in case the speed is high and you lose control.
Common Causes of Tyre Punctures
The most common cause of a tyre puncture could be slow or rapid deflation of a tyre, depending on its size, due to a sharp object penetrating it on the go.
Other factors that could cause a tyre puncture are:
- Failure of a tyre's valve stern.
- Breakage of the link between a tyre and rim owing to a collision with an external object.
- Excessively worn-out tread that could result in explosive tyre failure or debris from the road tearing through the tyre.
When (and When Not) to Repair a Tyre?
Tyre Puncture Repair is a tedious task and not as straightforward a process as it may seem. These are regulated by a certain BSAUl59 British Standard that defines limits to the repair materials that can be used and the total number of repairs that can be carried out on a tyre, based on the tyre size and location of the puncture.
A tyre must be thoroughly inspected before repair and a repair must not be attempted in case of any of the following symptoms:
- Tread depth below the legal limit of 1.6mm across the tyre's circumference.
- Broken structural integrity or run-flat damage.
- In case of any damage caused by an external object.
- Worn out, aged or deteriorated rubber.
- Exposed cords.
- Any sign of previous faulty repairs.
- In case you are uncertain about whether your car tyre must be repaired or not, seeking expert advice is a must.
Puncture repairs are carried out following NTDA and BSAUl59 regulations which also stipulate that:
- Tyres can only be repaired in the central ¾ of the tyre (known as the minor repair area).
- For tyres rated 'V' and above, only one repair is allowed.
Unfortunately, run-flat tyres are unrepairable. This is because they have reinforced sidewalls which means they can be driven on for a short time after picking up a puncture allowing you to travel to safety or your nearest tyre fitter. Unfortunately, when a run-flat tyre picks up a puncture it’s hard to tell if the structure of the tyre wall has been compromised because the punctured tyre could have been driven on for an excessive amount of time or at unsuitable speeds (over 30mph) but the added strength of the run-flat tyre can mask this damage. For this reason, it is not possible to carry out minor repairs to run-flat tyres as the tyre may no longer be safe to use.
Questions and Answers
When can tyre punctures be repaired?
The Puncture Location Is Important. Punctures can generally be repaired if they occur on the central portion of the tyre, in this case, the middle three-quarters of the tyre. If a puncture occurs outside this area, near to the tyre's sidewall, it cannot generally be repaired.
Can you repair a tyre with a nail in?
Depends on the size of the damaged area. This means it may be possible to repair a tyre that has been pierced by a nail or a screw, but if the damage is caused by a larger item such as a bolt or other metallic debris, the tyre may need to be replaced. This also means that tyre damage such as splits, cuts and gouges cannot be repaired.
Can you repair the sidewall of a tyre?
Unfortunately, even though any one of several objects or events can cause your tyre's sidewall to puncture, there's only one solution: replace the tyre. Unfortunately, sidewall punctures on passenger or light truck tyres can't be repaired.
Are puncture repairs safe?
Puncture repair guidelines. The sidewall cannot be safely repaired because it takes the most load when the tyre is in use. A repair, even if carried out by an expert, could potentially weaken the structure of the sidewall. This means a tyre damaged by a screw, nail or other sharp objects can usually be safely repaired.