Flat tyre: what to do

What does it mean to have a flat tyre?

A flat tyre is one that has lost almost all its air: the rim is resting on the squashed sidewall and the tyre can no longer support the weight of the vehicle. It's different from a tyre that's just a bit low, on which you can still move carefully.

The most common situation is finding it like this in the morning, with the car parked on the street or in a garage: the air has slowly escaped overnight.

Why has the tyre gone flat while parked?

A tyre that goes flat while the car is parked almost always has a slow leak that was already there: you didn't notice it while driving, but over several hours the air escaped completely.

• Puncture from a nail or screw picked up the day before.
• Valve faulty, loose or missing its cap.
• Leak between rim and bead, due to corrosion or hitting the kerb while parking.
• Sidewall damage after an impact, sometimes barely visible.
• Vandalism: valves unscrewed or cuts; in this case, document it with photos.

If the same tyre goes flat again a few days later, the problem is a slow leak that needs to be pinpointed precisely.

What should you do if you find a flat tyre?

With the car stationary, the main risk is making the damage worse by moving it. Proceed as follows:

1. Don't drive off and don't try to reach a petrol station or garage.
2. Look at the tread and sidewall: check for nails, cuts, bulges. Don't remove any objects stuck in it.
3. Check the valve: make sure the cap is there and that it isn't bent or split.
4. If the car is on the street in a dangerous spot (junction, bend, in front of a driveway), switch on your hazard lights.
5. Photograph the tyre and note down the size written on the sidewall.
6. Call for assistance, telling us where the car is and how to get to it.

Can I reinflate the tyre and set off?

Reinflating a flat tyre with a compressor only makes sense to see whether it holds pressure, not to drive off as if nothing had happened. If the tyre deflates again within a few minutes, the leak is significant and you must not drive.

If, on the other hand, it holds, you can at most drive a very short distance at low speed to a place where it can be checked, keeping an eye on the tyre pressure warning light. Be careful: if the tyre has been driven on deflated, even briefly, the internal structure may already be damaged with no obvious external signs.

Can a tyre that has gone flat be repaired?

A tyre found flat while parked is often still repairable, because it hasn't rolled deflated under load. A repair is possible if the cause is a small hole in the tread or the valve, and if the internal inspection shows no damage.

It becomes unrepairable, however, if the car has been moved a long way on the flat tyre, if there's a cut on the sidewall or if the internal plies are damaged. Read when a tyre can be repaired for the full criteria.

Flat tyre in a garage or courtyard: do we come out there?

Yes, assistance for a flat tyre is provided wherever the car is, including in a residential underground garage, a lock-up or a courtyard. It's the classic case for a mobile tyre fitter: you don't need to move the car or look for an open garage.

When you call us, let us know:

• whether the garage is underground and whether there are height restrictions;
• which floor the lock-up is on and whether there's space around the car;
• who can open gates or doors when we arrive.

How does SOS Tyre deal with a flat tyre?

SOS Tyre comes out straight away, in Milan and its province, 24/7, including nights, Sundays and public holidays. Call +39 377 326 0999 or fill in the assistance request with your location, vehicle, tyre size and a photo of the tyre.

The technician looks for the cause of the leak, assesses an on-the-spot repair if the tyre allows, or fits your spare wheel. If the car doesn't have a spare wheel, see also what to do without a spare wheel.