It is crucial to know when it is okay to have a tyre repaired and when a tyre should be replaced. If a tyre loses its air pressure, it must be removed from the wheel for a complete internal inspection to be sure it is not damaged. Tyres that are run even a short distance while flat are often damaged beyond repair.
Most punctures, nail holes or cuts up to 6mm can be repaired by trained technicians as long as the damage is confined to the tread. DO NOT repair tyres with tread punctures larger than 6mm, or any sidewall puncture. Also, never repair tyres which are worn below the wear indicator bars that are located on your tyre, as they won't conform to Australian Roadworthy Standards.
All tyre repairs should be handled by trained professionals. Your best bet is to keep a good spare tyre in your boot. Be sure that the spare is inflated to the proper pressure and adheres to Australian Roadworthy Standards.