Decking · Hot & humid

How a composite deck ages in New Orleans, LA

THE SHORT ANSWER

In New Orleans, sun is the main stress on a composite deck: UV ranks #9 of 25 cities we cover and there are about 106 days above 90 °F. Capped boards lighten noticeably in the first two years, then stabilize; dark colors also get hot underfoot. Model estimate: 23–29 years of service.

Main threat

Sun & UV

Climate profile

Hot & humid

Expected life

23–29 yrs

Wash

Spring & fall

Rainy days / yr

115

Days ≥ 90 °F

106

Simulated composite deck in New Orleans, LA after 10 years

Year 10Surface mildew in shaded areas

MODEL SIMULATION

New Orleans, LA · capped composite boards, south-facing, full sun

Drag through time 0 — 20 years

Color lossHigh

Surface wearModerate

Mildew / rotHigh

Fails first hereColor on full-sun boards

Storyboard

20 years in New Orleans, washed yearly

Composite deck in New Orleans, install: Install day — **Install**Install day

Composite deck in New Orleans, year 1: Slight early fade — **Year 1**Slight early fade

Composite deck in New Orleans, year 3: Slight early fade — **Year 3**Slight early fade

Composite deck in New Orleans, year 5: Color has lightened, then stabilizes — **Year 5**Color has lightened, then stabilizes

Composite deck in New Orleans, year 10: Surface mildew in shaded areas — **Year 10**Surface mildew in shaded areas

Composite deck in New Orleans, year 15: Surface mildew in shaded areas — **Year 15**Surface mildew in shaded areas

Composite deck in New Orleans, year 20: Surface mildew in shaded areas — **Year 20**Surface mildew in shaded areas

New Orleans’s wear fingerprint

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

Rainy days / yr114.5 · Typical

Avg humidity79% · High

Decay index100.9 · High

UV index (avg)1.4 · Typical

Freeze–thaw days3.8 · Low

Days ≥ 90 °F105.6 · High

NOAA station NEW ORLEANS AUDUBON (USW00012930, 6.9 km away), 1991–2020 normals · humidity & UV: NASA POWER.

What fails first here

1Surface mildewComposite does not rot, but pollen and dirt on shaded boards feed mildew — common in New Orleans’s damp climate. A wash in spring and fall prevents it.
2Heat underfootAbout 106 days a year top 90 °F; dark composite can get uncomfortably hot in full sun. Lighter colors help.
3Early color fadeCapped boards lighten in the first 1–2 years, then level off. Stronger here than average: UV rank #9 of 25.
4Gaps & fastenersBoards expand and contract with temperature; check hidden clips and end gaps every few years.

Upkeep

New Orleans maintenance calendar

Built from local normals: bar width is the share of days with rain; composite mainly needs washing.

Jan

Feb

MarWash & check for mildew

Apr

May

Jun

Jul

Aug

Sep

OctWash, clear gaps

Nov

Dec

Same city, other materials

How the alternatives age in New Orleans

Cedar deck

Expected life here: 10–13 yrs · main threat: moisture & decay

See it age in New Orleans →

Wood fence

Expected life here: 11–14 yrs · main threat: moisture & decay

See it age in New Orleans →

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

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Pinterest storyboard: composite deck in New Orleans, LA, new to year 20

Composite decks in similar climates

…and in very different ones

Denver, CO

Las Vegas, NV

Albuquerque, NM All 25 cities →

Questions New Orleans owners ask

How long does a composite deck last in New Orleans?

Our model puts a capped composite deck at 23–29 years in New Orleans, close to typical warranty terms. The boards outlast the look: expect some early fading and surface mildew in shade.

How often should you clean a composite deck in New Orleans?

Twice a year — in spring and fall. New Orleans’s damp climate makes mildew on shaded boards the most common complaint.

Is composite worth it over cedar in New Orleans?

In New Orleans our model gives untreated cedar 10–13 years and composite 23–29. The gap is smaller where rot is slow, so upkeep preference decides.

Why does wood turn white or pale in New Orleans?

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.