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 Materials cost $10-$30 or more a square foot, depending on the brand and style, or $3,200-$9,600 for 16'x20'. 2  CostHelper readers report spending $8,000-$11,500 on DIY materials for a composite deck, roughly $13.91-$28.57 a square foot, with an average of $19.34. A deck should be cleaned annually ($0.25-$1.50 or more a square foot) and a wood deck might require sealing ($1-$5 a square foot) or staining ($0.50-$7 a square foot) every 1-2 years, depending on the type of wood and the deck's exposure to sunlight and weather.