The table here shows the basic tyre tread depth requirements for the UK.
OTHER LEGAL REQUIREMENTS
Generally, with some exceptions for agricultural vehicles etc., it's against the law to use a tyre that:
- is not suitably inflated for the use to which the vehicle or trailer is put.
- has a cut in excess of 25mm or 10 per cent of the section width of the tyre, whichever is the greater, deep enough to reach the ply or cord.
- has a lump, bulge or tear caused by separation or partial fracture of its structure.
- is unsuitable in regard to the vehicle's use or to the types of tyres fitted to the other wheels (this does not apply to temporary use spare tyres).
- has any portion of the ply or cord exposed.
- is not maintained in fit condition for the use to which the vehicle or trailer is put.
- has a defect that might cause damage to the road surface or to persons on or in the vehicle or using the road.
Tyres degrade with age even if they aren't used very often but there are no hard and fast rules on when they should be replaced. Therefore, it's important to check tyres regularly for signs of aging such as cracks in the side walls, and replace them straight away.
EFFECT OF LESS TREAD DEPTH
Whilst the legal limit for cars is 1.6 mm, tests conducted by the Motor Industry Research Association (MIRA) found that once tyres are below 3 mm, stopping distances increase dramatically.
If you are in any doubt as to whether your tyres are roadworthy, have them checked by a reputable garage/tyre fitter or indeed by ourselves when we visit and we/they will be able to advise you.