I took a couple of sections of the Kronotex Shenendoah Oak(cheapest line) and joined them together. Sitting them on a flat surface I poured some water on top of the joint and let it stand there all night. The water did not penetrate the surface and even better it did not seep into the joint at all which leads me to believe no poly or glue is necessary. The only thing worth worrying about is water getting under the floor and hoping it won't get to the wood. hehe.