Composite Decking Calculator: Trex vs. TimberTech Cost Estimator

Why Trex and TimberTech Quotes Can Differ by Thousands

You may have requested quotes for the same deck footprint from two contractors and gotten numbers $5,000 apart, even though both said "composite decking." That gap almost always comes down to which brand and which tier within that brand — "composite decking" isn't one product, it's an entire category spanning $2.50 to $10+ per linear foot in material cost alone, before labor even enters the picture.

Trex and TimberTech are the two biggest names in the category, and they're structured almost identically: each offers an entry-level line, a mid-tier line, and a premium line, with TimberTech's top tier (AZEK) built from PVC rather than wood-plastic composite. This calculator handles both brands and all their tiers, so you can compare apples to apples instead of guessing at where a quote falls.

How Composite Decking Boards Are Sized and Spaced

Nearly every composite deck board on the market shares the same basic dimensions: about 5.5 inches of actual face width, sold in standard lengths of 12, 16, and 20 feet. Boards install with a small gap between them — typically 1/8" to 1/4" — for drainage and thermal expansion, which means the real coverage per board row is closer to 5.75 inches than the nominal 5.5.

That small gap matters for material math: it's why decking calculators use an "effective width" slightly larger than the board's nominal width when converting deck area into linear footage needed.

How to Calculate Composite Decking Boards Needed (step by step)

Every accurate materials estimate follows the same chain, whether you're buying Trex, TimberTech, or any other composite brand.

The calculator above runs all four steps the moment you enter your deck dimensions and board length.

A Worked Example: 300 Sq Ft Deck

Let's price a 20×15 ft deck (300 sq ft) using 16-foot boards and Trex Select/Transcend (mid-tier), with a standard 10% waste allowance.

That installed range matches the widely cited 2026 national figures for a 300 sq ft composite deck almost exactly — a good sanity check if a contractor quote comes back well outside that window.

Trex vs. TimberTech: Comparing Product Tiers and Pricing

What if you're trying to decide which brand fits your budget and priorities? Trex wins on price at every comparable tier, while TimberTech generally wins on heat performance and warranty length — especially in its AZEK PVC lines.

Long-Term Maintenance and Lifespan: Trex vs. TimberTech

What if you're weighing the higher upfront cost against years of ownership? Both brands are built to outlast pressure-treated wood by a wide margin, but they get there slightly differently. Trex's wood-plastic composite core resists rot and insects but can absorb a small amount of moisture at cut edges if they aren't properly capped or sealed during installation. TimberTech's PVC and capped polymer lines resist moisture absorption almost completely, which is part of why TimberTech boards typically outlast Trex composite boards by 5-10 years in harsh, wet, or freeze-thaw climates — though both brands comfortably exceed 25 years of service life under normal conditions.

Maintenance itself is minimal for either brand compared to real wood: an occasional soap-and-water cleaning is typically all that's needed, with no annual staining or sealing required the way a pressure-treated or cedar deck demands. This is the core value proposition of composite decking overall — the 2025 Zonda Cost vs Value Report shows composite decks carrying a roughly 27% price premium over wood at installation, a gap that narrows or closes over a 20-year ownership window once you factor in the wood deck's recurring restaining costs.

Both brands are also relatively eco-conscious choices: Trex highlights 95% recycled material content and a large-scale recycling program, while TimberTech incorporates recycled content in its composite lines alongside its advanced PVC manufacturing — a consideration worth factoring in if sustainability is part of your decision alongside cost.

Can You DIY Composite Decking or Should You Hire a Pro?

What if you're comfortable with basic carpentry and want to skip the labor cost? Composite decking is genuinely more DIY-friendly than many other exterior projects — both major brands offer hidden fastener systems (Trex's Hideaway® and TimberTech's CONCEALoc®) specifically designed for straightforward, screw-free-face installation, and composite boards don't warp or split the way lumber can during a first attempt.

What tips the decision toward hiring a pro? TimberTech's heavier PVC boards and more intricate premium designs often benefit from professional installation experience, which is part of why TimberTech's typical labor rate ($9-12/sq ft) runs higher than Trex's ($7-10/sq ft). Any deck requiring new footings, a raised structure over 30 inches, or local permit sign-off is also a strong signal to bring in a licensed contractor rather than go fully DIY.

Common Mistakes to Avoid When Ordering Composite Decking

• ✕Comparing material cost only, ignoring installed cost. A cheaper board doesn't always mean a cheaper project once labor, framing, and fasteners are added — compare fully installed ranges, not just per-board pricing.
• ✕Forgetting the drainage gap in the materials math. Using the nominal 5.5" board width instead of the ~5.75" effective width (including gap) slightly undercounts linear footage needed.
• ✕Mixing board lines within the same deck. Different collections within a brand can vary slightly in thickness and profile — stick to one product line for a consistent, warranty-compliant installation.
• ✕Skipping the heat performance question in sunny climates. A budget composite board in full afternoon sun can get uncomfortably hot underfoot — if that's a concern, TimberTech's PVC lines or lighter board colors in either brand perform meaningfully better.
• ✕Assuming board length equals waste-free coverage. Deck layouts rarely divide evenly into whole board lengths — the leftover cutoffs from each row is exactly what the waste factor in the calculator accounts for, and skipping it under-orders material almost every time.