According to the National Institutes of Health and many other sources, the stress response is caused. by hormones. Hormones are chemicals, produced by glands and carried through the bloodstream, that. affect the activities of organs in the body.
Composite Decking Costs. 1  Average: $35 per square foot. 2  For polythylene-based composite decking, the average cost per square foot is $7.82. 3  For polypropylene-based decking, the average cost is $8.68 per square foot.
The magazine found a total national average cost of $9,539. It used the following criteria to come up with the average national cost for materials and installation of a composite deck: Add a 16-by-20-foot deck using pressure-treated joists supported by 4x4 posts anchored to concrete piers.