Repairing a tyre is not as straightforward as you first might think. Tyre repairs are covered by BSAU159f:1990 which splits repairs into two categories - minor repairs and major repairs. The British Standard also defines limits to the location, size and number of repairs that can be carried out and makes recommendations also on the repair materials to be used.

A tyre must always be checked thoroughly before it is repaired. If the tyre displays any of the following, it should not be repaired:

• Illegal tread depth *
• Run flat damage
• Secondary damage - caused by the injuring object
• Ageing/deterioration of tyre rubber
• Bead damage
• Exposed cords

* Below 1.6mm across the central 3/4 of the tyre tread throughout the entire circumference.

---