Decking · Mixed

How long does a pressure-treated deck last in Dallas, TX?

THE SHORT ANSWER

In Dallas, sun does most of the damage. UV here ranks #12 of 25 cities we cover, with about 108 days a year above 90 °F. Unsealed boards bleach to a pale silver and open up surface checks; with a decay index of only 47.4, rot is a slow, secondary risk. Model estimate: 11–14 years unsealed, 14–18 years sealed on schedule.

Main threat

Sun & UV

Climate profile

Mixed

Expected life (unsealed)

11–14 yrs

Fully gray by

Year 2

Best seal window

Jul – Aug

Sealed on schedule

14–18 yrs

Simulated pressure-treated deck in Dallas, TX after 10 years

Year 10Soft spots — probe for rot, heavy mildew, deep checks

MODEL SIMULATION

Dallas, TX · treated southern pine boards, south-facing, full sun, no sealant

Drag through time 0 — 20 years

Color lossSevere

Surface checkingSevere

Mildew / rotHigh

Fails first hereBoard surfaces: checks, splits and cupping

Storyboard

20 years in Dallas, unsealed

Pressure-treated deck in Dallas, install: Fresh, green-tinted boards — **Install**Fresh, green-tinted boards

Pressure-treated deck in Dallas, year 1: Silvering begins — **Year 1**Silvering begins

Pressure-treated deck in Dallas, year 3: Checks and some warping — **Year 3**Checks and some warping

Pressure-treated deck in Dallas, year 5: Mildew in shade, checks and some warping — **Year 5**Mildew in shade, checks and some warping

Pressure-treated deck in Dallas, year 10: Soft spots — probe for rot, heavy mildew, deep checks — **Year 10**Soft spots — probe for rot, heavy mildew, deep checks

Pressure-treated deck in Dallas, year 15: Soft spots — probe for rot, heavy mildew, deep checks — **Year 15**Soft spots — probe for rot, heavy mildew, deep checks

Pressure-treated deck in Dallas, year 20: Soft spots — probe for rot, heavy mildew, deep checks — **Year 20**Soft spots — probe for rot, heavy mildew, deep checks

Dallas’s wear fingerprint

Each bar is scaled to the highest of the 25 cities we cover; the black line marks the median.

Rainy days / yr82.2 · Low

Avg humidity69.2% · Low

Decay index47.4 · Typical

UV index (avg)1.4 · Typical

Freeze–thaw days21.8 · Typical

Days ≥ 90 °F107.6 · High

NOAA station DALLAS FAA AP (USW00013960, 7.3 km away), 1991–2020 normals · humidity & UV: NASA POWER.

What fails first here

1Checks, splits and warpingStrong UV (rank #12 of 25) dries and shrinks the surface faster than the core, opening fine cracks.
2Mildew & algaeFrequent rain and 69% average humidity keep shaded boards damp; dark spots start near walls, planters and gaps.
3Rot at board ends & joistsSlow here (decay index 47.4), but ends and joists under planters still fail first.
4Sun bleaching & raised grainSurface fibers break down under strong sun and wash away, leaving a pale, fuzzy texture.

Upkeep

Dallas maintenance calendar

Built from local normals: bar width is the share of days with rain; sealant needs 2–3 dry days between 50 and 88 °F.

Jan

Feb

MarInspect ends & fasteners

Apr

May

JunWash off mildew

JulSeal / stain

AugSeal / stain

Sep

OctClear leaves & gaps

Nov

Dec

Same city, other materials

How the alternatives age in Dallas

Cedar deck

Expected life here: 15–19 yrs · main threat: sun and UV

See it age in Dallas →

Composite deck

Expected life here: 23–30 yrs · main threat: sun and UV

See it age in Dallas →

Wood fence

Expected life here: 14–18 yrs · main threat: sun and UV

See it age in Dallas →

Vinyl fence

Expected life here: 22–28 yrs · main threat: sun and UV

See it age in Dallas →

Pin-ready

Save it for when you build.

The 20-year storyboard as a tall pin, linking back to this page.

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Pinterest storyboard: pressure-treated deck in Dallas, TX, new to year 20

Pressure-treated decks in similar climates

…and in very different ones

Buffalo, NY

Seattle, WA

Denver, CO All 25 cities →

Questions Dallas owners ask

How long does a pressure-treated deck last in Dallas?

Our model puts it at 11–14 years unsealed and 14–18 years if it is sealed every 2–3 years. The national typical range is 10–15 yrs; Dallas’s sun and UV profile is why the local number differs.

When is the best time to seal a pressure-treated deck in Dallas?

July and August: the months with the fewest rainy days while average temperatures sit between 50 and 88 °F. Most sealants need 2–3 dry days to cure.

Cedar or pressure-treated: which lasts longer in Dallas?

Our model gives an unsealed pressure-treated deck 11–14 years here and untreated cedar 15–19 years. Where rot is slow, cedar’s stability wins: treated pine checks and warps faster in sun and frost.

Why does wood turn white or pale in Dallas?

UV breaks down lignin at the surface; rain and wind wash the loose fibers away, leaving a bleached, silvery layer. It is cosmetic until checks open up.

Model simulation, not a guarantee: south-facing, full sun, no shade or ground-contact surprises. How it works.