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.
1 Some of the factors affecting the total cost for any type of deck include the height; shape; number of levels; railing length, material and style; steps, staircases and landings; benches, lighting or other built-in features; and whether an old deck needs to be demolished and hauled away. Composite deck installation can cost $25-$70 or more a square foot (8,000 -$22,400 for 16'x20).