A tire patch can't be used on every part of a tire. Specifically, you should pay close attention to how far away the punctured hole is from the shoulder or sidewall of your tires. This is crucial, as the inner steel belt of the tire begins and ends near this edge, intersecting the shoulders and sidewall of the tire. If the puncture is 1/2 inch or more away from the edge of the tire treads, then it should be safe to patch up. Otherwise, if the puncture is less than 1/2 inch away from the starting point of the steel belt on the sidewall or should, it's not safe to patch up.