Dear Veritas:
The difference between purchasing a laminate floor that is 8mm and 7mm is how stable the product will be. Because an 8mm laminate is thicker and therefor more stable its warranty is better protected in heavy traffic areas, such as the downstairs of a house. Usually it is a good idea to purchase 8mm flooring for basemant or first level installation and 7mm flooring is generally fine for upstairs.
Feel free to visit my site and go directly to Shaw Inc. through it to see the full list of warranties and specifications so that you may have a better understanding of this.
www.brandflooring.com