Identification

• The presence of dry rot can be identified with a close examination of the tire walls. When dry rot occurs, the walls of the tire will crack. Generally the cracks start out small and look similar to a spider web. Eventually the dry rot will increase the size of the crack and cause the tire sidewall to split open. The tire is no longer safe to drive if cracking to this degree has occurred--the tire needs to be replaced.
  
  

Ozone

• Ozone is part of the air that we breathe every day and we couldn't survive without it. However, this important natural gas can cause serious damage to tires. Manufacturers blend waxes into tire rubber to help protect against ozone gasses, and as tires flex while rolling down the road these protective waxes are pushed to the surface of the tire. Manufacturers refer to this process as "blooming." When tires are parked for a long time the blooming effect doesn't take place. This the ozone gas to wear away whatever is on the surface. When ozone reaches the polymer of the tire, the tire will dry out and begin to crack.
  
  

Ultraviolet Light

• Tires are black to help protect them against ultraviolet light. A UV stabilizing compound is mixed in when tires are manufactured. This compound is referred to as a competitive absorber and works to absorb UV rays and convert it into heat which can be harmlessly dissipated. However, the competitive absorber chemicals in a tire will eventually be used up. Then the tire will begin to turn a gray color and the drying and cracking process of dry rot will begin.
  
  

Chemicals

• Many chemicals that are advertised as tire dressings are made with petrochemicals and do not contain any UV protection. Petrochemicals will strip away the wax that was manufactured into the tire to protect it from UV rays. Products with silicone oils will also strip away the protective oil.
  
  

How to Fix Dry Rot

• If the dry rot is still in the early stages, there are products that can be absorbed into the tire to replenish the rubber with the essential waxes needed to prevent cracking. These products do not contain any petrochemicals or silicone oils. Although these products may extend the life of a tire in the early stages of dry rot, several applications of the product may be necessary. If tires are in the advanced stages of dry rot and cracking has begun, the best and only fix is to replace the tires.