TimberTech AZEK Vs TimberTech PRO Decision Guide

Why this matters

TimberTech sells two structurally distinct decking platforms under one brand: AZEK (Vintage, Arbor, Harvest) is a 100 percent cellular PVC product with no wood content; TimberTech PRO (Reserve, Legacy, Terrain) is a capped composite with a wood-flour/recycled-polymer core and a four-sided PVC cap. The two look similar on a sample but behave differently on a hot south-facing deck, in a saltwater pool surround, on a long cantilever, and at warranty claim time. Quoting AZEK when the budget is PRO loses you the job; quoting PRO when the spec needs AZEK gets you a warranty fight 18 months in when capillary moisture finds the cut end of a composite core. This guide pins down the engineered differences from the current TimberTech Installation Guide and the ICC-ES ESR reports so you can write a clean spec.

Material core and density

AZEK is cellular PVC at roughly 38 lb/ft3. There is no wood in the core; freeze-thaw is a non-issue and there is no mold substrate. Cut ends are the same material as the surface - you can rip a board lengthwise and the cut edge looks like the field. PRO is a wood-plastic composite at roughly 60 lb/ft3 under a four-sided PVC cap. Cut ends expose composite core, which is sealed by the rim cap but not by the field cap; field practice is to keep cut ends off ground contact and seal stair-nosing cuts with the manufacturer-approved end seal.

The density difference shows up at every step. AZEK is roughly 35 percent lighter per linear foot of 5/4 x 6, which matters for second-story deliveries and for solo installers. PRO has more thermal mass and feels more like traditional decking underfoot. Neither is structural; both require code-compliant joists per ICC-ES ESR-1667 (TimberTech PRO) and ESR-2967 (TimberTech AZEK).

Heat build and surface temperature

This is the single biggest reason to push a customer up the line. Per TimberTech published thermal data and third-party testing summarized in TB-15:

• AZEK Vintage in a light color (Coastline, Weathered Teak): roughly 12 to 18 F below comparable PRO Legacy under identical insolation.
• AZEK Arbor and Harvest: roughly 8 to 12 F below comparable PRO Terrain.
• PRO Reserve in a light color: roughly equivalent to AZEK Arbor.
• PRO Legacy and Terrain in dark colors (Espresso, Mocha): the warmest products in the line; barefoot-uncomfortable above 90 F ambient with direct sun.

If the deck faces south or west and the homeowner walks barefoot, AZEK in a light color is the only specification that will not produce a callback.

Span rating and joist spacing

Per the current TimberTech Installation Guide and the ESR reports:

• AZEK and PRO 5/4-inch boards, residential perpendicular install: 16 in. o.c. maximum.
• AZEK and PRO 5/4-inch boards, diagonal install: 12 in. o.c. maximum.
• AZEK and PRO 2x6 boards (Vintage Quick-Clip platform): 24 in. o.c. perpendicular permitted for residential.
• Stair treads, both lines: 10 in. o.c. minimum, with double-rim support at nosing.
• Commercial occupancy under ICC-ES ESR-1667: 12 in. o.c. perpendicular for PRO; AZEK is rated commercial at 16 in. with mid-span blocking per the ESR.

If the inspector asks for the ESR number, you must hand them ESR-1667 for PRO and ESR-2967 for AZEK. The two are not interchangeable.

Fastener systems

Both lines use the TimberTech CONCEALoc hidden fastener with grooved boards, and FUSIONLoc on the universal-fastener-channel boards. AZEK Vintage uses a slightly different groove profile from PRO Legacy - the CONCEALoc clip is the same but the engagement depth differs. Per TB-08, mixing brands of grooved board with TimberTech clips voids the AAMA labor portion of the warranty. Cortex plugs are accepted on all lines; AZEK plugs are PVC and match perfectly, PRO plugs are capped composite and match the cap color. Stainless 305 or 316 fasteners are required at saltwater pool surrounds and within 1500 ft of saltwater per TB-22; standard coated screws are permitted inland.

Warranty tiers

Per the current TimberTech Limited Lifetime Residential Warranty and Limited Residential Warranty:

• AZEK Vintage, Arbor, Harvest: 50-year limited residential fade-and-stain, lifetime limited residential product warranty.
• PRO Reserve: 50-year limited residential fade-and-stain, lifetime limited residential product warranty.
• PRO Legacy: 30-year limited residential fade-and-stain, 30-year limited residential product warranty.
• PRO Terrain: 25-year limited residential fade-and-stain, 25-year limited residential product warranty.

The fade-and-stain threshold is 5 Delta E units. PRO Terrain in dark colors has historically been the line with the highest fade-claim rate; quote it only when budget is the constraint and document the warranty term on the contract.

Decision tree by job type

• Saltwater pool surround, splash zone: AZEK only. No composite core means no capillary moisture path, full stop.
• Hot southern-exposure deck, barefoot use: AZEK Vintage or Arbor in a light color.
• Rooftop amenity deck on pedestals: AZEK Vintage. The lighter weight saves structural load and the PVC core handles ponding moisture without consequence.
• Standard suburban deck, average exposure, budget-conscious customer: PRO Reserve in a mid-tone. Best price-to-warranty ratio in the line.
• Heavy commercial traffic (restaurant patio, multi-family common deck): PRO Reserve at 12 in. o.c. per the commercial ESR rating. AZEK commercial requires the mid-span blocking detail.

What to put on the estimate

State the product family, sub-line, color, profile, and warranty term. "TimberTech composite" is not a spec; "TimberTech AZEK Vintage English Walnut, grooved 5/4 x 6, 16 in. o.c., CONCEALoc hidden fasteners 305 stainless, 50-year fade-and-stain" is. AZEK costs more at the supply house; do not eat the delta because the takeoff was sloppy.

References

1. ICC-ES ESR-1667: TimberTech PRO Composite Decking Evaluation Report.
2. ICC-ES ESR-2967: TimberTech AZEK Cellular PVC Decking Evaluation Report.
3. TimberTech Installation Guide (current edition), Span Tables.
4. TimberTech Limited Lifetime Residential Warranty (current edition).
5. TimberTech Technical Bulletin TB-15: Surface Temperature Performance.
6. TimberTech Technical Bulletin TB-22: Saltwater and Coastal Fastener Requirements.