cost of a 20x5 foot deck
1 The total project cost for a Trex deck will be from $1,500 to $2,200 for a 250-square-foot deck. 2  Trex Select of basic quality averages approximately $7 per square foot.3  Trex Enhance of higher quality is approximately $8 per square foot.4  Trex Transcend, the highest grade, ranges between $9 and $9.50 per square foot.o get an idea of what this means to consumers, an estimated 140,000 plastic bags are in a 500-square foot Trex deck. 1  The total project cost for a Trex deck will be from $1,500 to $2,200 for a 250-square-foot deck. 2  Trex Select of basic quality averages approximately $7 per square foot.