Over time a new driveway or recently cleaned and sealed driveway can start to look dirty and show up with tyre marks. We have heard the following questions many times from customers:

Why do car tires leave black marks on my sealed driveway? How do I avoid this and remove the existing tyre marks?

The marks caused by tyres on driveways are a phenomenon called “plasticizer migration.” Plasticizers are polymer compounds added to rubber, glue and plastic to make them flexible. The rubber used to make car tyres contains plasticizers to improve traction.

But when the car is driven, the tyres heat up, causing the plasticizers to soften and leach out of the tyre. When a hot tyre is parked or driven on certain types of sealers, the plasticizers migrate into and discolour the sealer.

The better the tyre quality, the higher the quantity of plasticizer-and the greater the chance for hot tyre marking. Lower-quality tyres are harder and contain less plasticizer, so they usually result in less hot tyre marking on sealers.

One option is to switch tyres, however, if switching to harder tyres is not in the cards, then consider using a different type of sealer. When a sealer cures, the resins cross-link, forming a cross-linking matrix. All sealers exhibit some degree of cross-linking. The greater the cross-linking, the denser the coating and the more resistant the sealer will be to hot tyre marking.

Most hot tyre marks occur on acrylic sealers, which exhibit minimal cross-linking. Using a higher-solids acrylic or a high-solids, or a highly cross-linked sealer will reduce hot tyre marking greatly. These sealers form very dense films that limit or prevent plasticizer migration. Striking a good balance of sealer durability and density will make all the difference when sealing driveways and concrete floors where there is vehicle traffic.

Contact Barefoot Concrete to discuss your situation and where we can help you to clean the tyre marks off your driveway and to reseal it with a better quality sealer to minimize the hot tyre marks.

We also recommend that if you want to get rid of discolouration from hot tyre marking, you can first attempt to clean the surface with a concrete cleaner, as long as it’s compatible with your concrete or concrete coating, and this may end up being all that’s needed, depending on the level of discolouration.

If the discolouration has migrated deep into the sealer, you may need to loosen the affected areas with a solvent or totally remove the sealer by pressure cleaning or using an acid wash or a chemical stripper.