Tyre companies reckon on average we’ll suffer a punctured tyre every five years. Sometimes nails or other sharp road debris cause these punctures and the tyre can be repaired. But it depends how far you’ve driven on it.
What happens when you get a puncture?
Unless you’re driving on a run-flat tyre, the tyre’s sidewall (the area between the tread and the wheel that’s perpendicular to the road) isn’t stiff enough to hold the wheel off the ground. The air inside it does this; the sidewall simply helps to contain that air. When the air escapes, the weight of the car pushes down on the sidewall causing it to flex far more than it’s designed to. The more you drive on it, the more likely this flexing is to damage the sidewall permanently.
You can’t repair a tyre’s sidewall
The sidewall of the tyre is made of pure rubber and designed to flex a bit. It’s this that helps some tyres to give their cars a more comfortable ride. The area joining tyre and wheel is called the bead and made of various materials including nylon and steel. These can suffer if the weight of the car is forced onto them because of a lack of air pressure.
Why you can’t repair the sidewall
As the sidewall flexes while the tyre’s being driven on, any repair wouldn’t last for long before failing. As a consequence, it’s illegal to repair tyre sidewalls that have been damaged.
How do you know if you’ve suffered a puncture?
First, you might notice that your Tyre Pressure Monitoring System is warning you there’s something wrong. But you must have set it up properly for this to happen. If you haven’t, you’ll probably feel an uncomfortable vibration through the steering wheel. Should the punctured tyre be on a front wheel, the car might be difficult to steer; if it’s a rear wheel, the back of the car will feel unsettled, as if that wheel is driving on a slippery surface. Assuming you don’t have your sounds on too loud, you’ll probably hear a flapping noise as the loose rubber of the punctured tyre slaps the road surface.
What to do if you suffer a punctured tyre?
You should presume that the flat tyre can be repaired. But you’ll only be able to do this if you stop driving on it as quickly as possible. The moment you detect a puncture, you should be looking for somewhere to pull over safely. Don’t jam on the brakes, you might lose control of the car. Slow gently while indicating what you plan to do. Then pull off the road as soon as it’s safe to do so and you can stop somewhere where your stationary car isn’t endangering other road users.
After the puncture
Once you’ve had your car recovered or changed the wheel, have a specialist tyre technician check the puncture tyre. They’ll be able to tell you if it can be repaired or not.