Definition of Tyre Repairs

Tyre repairs should only be carried out by specially trained personnel using professional equipment.

It is important to remember before any tyre can be repaired, it must be checked thoroughly to ensure it is suitable for repair. Ensure that you check for the following:

  • Legal tread depth (UK car: 1.6mm across central 3/4 of the tyre tread throughout the entire circumference)
  • Run-flat damage
  • Secondary damage – caused by the injuring object
  • Ageing/deterioration of tyre rubber
  • Bead damage
  • Exposed cords
  • Faulty/poor previous repairs

If the tyre has experienced any of the above, it should not be repaired. The above list is not exhaustive. Inspection is vital and the use of common sense – if you have doubts about whether or not a tyre should be repaired, do not repair it.

Tyre repairs are covered under British Standard BS AU 159f and below is an excerpt from this standard showing some of the limitations that apply regarding the area in which a tyre can be repaired (known as the “T” area) and size / number of repairs:

The repairable area T is defined as a percentage of the tyres nominal section width and is dependant on the type and size of the tyre

Chart to the left shows the percentage of the T area for different size/types of tyres

This chart shows the limitations that apply to the number of repairs allowed to a tyre and also the limitation on the size of the injury