What a puncture repair involves

Where the damage is matters

A repair is only possible when the hole is in the central tread area and within the size limits set by the British Standard for tyre repairs. Damage to the sidewall or shoulder cannot be safely repaired because that part of the tyre flexes constantly.

The tyre comes off the wheel

A proper repair means removing the tyre so the inside can be inspected for hidden damage, then fitting a combined plug and patch from the inside. A plug pushed in from the outside without inspection is a temporary fix at best.

If the tyre has been driven on flat for any distance, the inner lining may have broken up, in which case it needs replacing rather than repairing.