Tyre Safety: Repair or Replace?

• Tyres-Tips/Guides

Potholes happen. Nails and broken glass happen. Unfortunately there’s little you can do to prevent a damaged tyre besides not driving on the road! But your budget is low this month and you’re wondering if you could just repair that tyre rather than replace it.

Considering the overall condition of the tyre, the first step is to determine the type and extent of the damage.

Types and Causes of Tyre Damage

The size and type of damage to a tyre matters a great deal – damage from a pothole can be substantially worse than a puncture from a nail. Aside from the general wear and tear to a tyre, there are four main types of tyre damage and most common reasons they occur:

1. Punctures
1. When a sharp object such as a nail pierces through a tyre’s tread area deep enough, a hole forms and air escapes
2. Sidewall bulge 
1. Continued driving on a punctured tyre
2. A hard impact such as driving over a pothole or into a pavement can weaken the sides of your tyre and cause a bulge at the location of impact
3. Cracks 
1. General wear and tear due to age
2. Ultra violet rays from prolonged sun exposure causes the rubber to harden and become brittle
3. Infrequent driving and having the car standing still for long periods
4. Burst tyres 
1. The sudden impact on a tyre when driving over an object at high speed
2. An under-inflated tyre increases road friction and heat, and together with the pressure from the weight of the car, causes the tyre to burst
3. Even cracks that are not attended to result in a burst tyre

Read: Can Tyre Blowouts be Prevented?

What Type of Tyre Damage is Safe to Repair?

Small punctures in the outer wall or tread of the tyre made by objects like a nail or screw are easily repairable.

Internal damage, sidewall damage, deep cuts, huge gouges, or a split from a burst tyre are not repairable.

As a rule of thumb, holes larger than about 5 - 6mm across should not be considered safe for repair.

*If the hole is no bigger than 5 – 6mm

Tyre Puncture Repair Methods

When the object that  punctured the tyre is removed, the rubber closes up and the location of the puncture is hardly visible. There are three ways to repair a small puncture:

1. Plug
2. Patch
3. Plug and patch combination

For proper repair, the inside of the tyre should be inspected to see what damage has occurred, if any. In order to inspect the cavity of the tyre for damage, the tyre must be removed from the rim.

In the patch repair method, the tyre technician removes the tyre from the rim, locates the area of damage, and prepares the surface for repairing by means of a patch. In the plug method however, the tyre is not removed from the rim and the puncture is repaired from the outside.

Neither the plug or patch method alone is sufficient to ensure a fully safe and proper puncture repair. This is why the combination method is suggested by tyre experts.

In Summary

Don’t take risks with safety. If a tyre was badly damaged, it’s best to replace it. Small punctures that can be repaired safely may be fine to go for a few thousand more kilometres. However, it’s important that any repairs to a tyre must be done professionally by a qualified mechanic.

Disclaimer: This information is for educational, or entertainment purposes only. It must not be construed as advice, legal, financial, or otherwise. We do not make any warranties about the completeness, reliability, and accuracy of this information. The views expressed in this article are the views of the author and not necessarily the views of Supa Quick.