Trex Decking Cost by Square Foot Deck Dimensions Deck Square Footage Trex Decking Cost Range* 10x10 100 $1,500 - $3,000 12x12 144 $2,160 - $4,320 14x20 280 $4,200 - $8,400 16x20 320 $4,800 - $9,600 2 more rows How Much Is Trex Decking In 2024? - Forbes forbes.com https://www.forbes.com � outdoor-living � trex-decking-... forbes.com https://www.forbes.com � outdoor-living � trex-decking-... Trex Decking Cost by Square Foot Deck Dimensions Deck Square Footage Trex Decking Cost Range* 10x10 100 $1,500 - $3,000 12x12 144 $2,160 - $4,320 14x20 280 $4,200 - $8,400 16x20 320 $4,800 - $9,600 2 more rows