Trex Decking Calculator

How composite decking is priced

Composite pricing is tiered by cap technology and aesthetics, not by structural performance — every line in a brand's range carries the same load. What you pay more for is a better shell (four-sided capping instead of three), deeper multi-tonal streaking, and a longer fade-and-stain warranty. That's why Trex Enhance Basics and Trex Transcend can differ by more than $6 per square foot while installing identically.

2026 board-only material pricing by line

These are 2026 retail averages for in-stock colors. Special-order colors and 20 ft lengths run 5-15% higher, and dealer pricing on full-pallet quantities can undercut big-box shelf pricing.

Trex cost by deck size

The same arithmetic as the calculator above, run for common deck sizes with 16 ft grooved boards and hidden clips. "Boards + fasteners" is the decking, clips and fascia only; "installed" adds a pressure-treated frame and labour. Ranges are the calculator's own −8%/+12% and −10%/+15% bands.

Worked example, 12x16 in Trex Select: 12 ft of width at 5.5 in plus a 3/16 in clip gap is 26 rows; 16 ft each plus 8% waste is 449 linear ft, or 29 boards at 16 ft. At about $7.90 per sq ft the boards come to $1,638, then 2 boxes of clips ($190) and fascia for the 56 ft perimeter ($252).

Does this calculator price Trex RainEscape?

No. RainEscape is Trex's under-deck drainage system: a network of troughs and gutters beneath the decking that carries rain and snow melt away so the space below the deck stays dry. Trex sells it in brown or black with a 25-year warranty (trex.com, checked October 2026). It is priced separately from the decking, so ask the dealer for a takeoff using your deck's length and width, and budget it as its own line next to the estimate above.

Grooved versus square-edge boards

Grooved boards accept hidden clips that set a consistent 3/16-inch gap and leave no visible fasteners — the finish most people want. Square-edge boards are face-screwed with color-matched composite screws and are required for the first and last board, stair treads, and picture-frame borders. Order both: roughly 90% grooved and 10% square-edge for the perimeter, plus fascia board for the rim.

Framing requirements composite adds

Composite is heavier and less stiff than wood, so the frame under it is not optional. Nearly every brand requires joists at 16 inches on center for perpendicular boards and 12 inches on center for 45-degree layouts and stair treads. Blocking is required at butt joints and under picture-frame borders. Skipping this is the single most common cause of a denied warranty claim, and it also produces the bouncy feel people wrongly blame on the boards.

Composite versus wood over 25 years

Composite costs roughly $18 more per square foot up front but eliminates the sand-and-stain cycle that wood needs every two to three years at $2-$4 per square foot each time. Over 25 years, total cost of ownership lands within a few thousand dollars of each other on a typical 300 square foot deck — the real decision is whether you'd rather pay money now or spend weekends later. Run your own numbers in the composite vs wood calculator or read the best composite decking guide.