A flat tyre can be caused by various things. The most common is a
tyre puncture, due to driving over a nail or sharp object, for example. This can happen while driving on the road or manoeuvring in a private space like a car park. In some cases, it may be possible to repair the punctured tyre without replacing it.
Another common cause is a
problem with the tyre valve, for example if the stem is loose or leaking, or if the valve is damaged and can no longer maintain the correct tyre pressure.
Excessive tyre wear can also cause this problem, or a leak from the tyre bead (the part that sits on the rim).
Other possible causes of a flat tyre are
acts of vandalism, collision with an object that causes the tyre and rim to bump or
over-inflation of the tyre.
Less common causes include a leak from alloy wheels, driving over a pothole or speed bump, or the
sudden collapse of the tyre’s structure.