Trex decking is warranted for 25, 35, and 50 years, depending upon the collection used. All three Transcend lines are backed by a 50-year limited warranty; Select a 35-year limited warranty, and both Enhance Naturals and Basics come with a 25-year limited warranty. When installing the deck boards, it is important to follow the installation guidelines, in part so you don’t void the warranty.. You’ll extend the life of your deck by giving care to your substructure as well.