The definition of symbiosis has varied among scientists. Some believe symbiosis should only refer to persistent mutualisms, while others believe it should apply to any type of persistent biological interaction (i.e. mutualistic, commensalistic, or parasitic).
The Golden Pledge, which is a System Plus Warranty with a 20 year leak guarantee, can pay for itself within the first ten years, sometimes many times over. The System Plus transforms the normal warranty by removing the small print.
The lifetime GAF products are covered for 50 years under this policy. I call it that because it's just like an extended insurance policy. All other products carry a 100% coverage for 20 years. The twenty year leak protection plan under the Golden Pledge is more than paper. It is all the accessories GAF has to offer to make a full and complete roof system designed to withstand every type of rain even Mother Nature can throw at the roof except for storms with names like Katrina or Genghis Khan.