Decking · 25 cities

Composite vs wood deck: which lasts longer in your climate?

THE SHORT ANSWER

Across the 25 US cities we model, a composite deck lasts 22–33 years and a pressure-treated deck 9–15 years unsealed. The composite deck outlasts it in every city, and climate decides by how much: the gap is widest in Atlanta, GA (24–31 vs 9–12 years) and narrowest in Las Vegas, NV (22–29 vs 12–15). Wood here means the two common choices: pressure-treated pine and cedar.

Simulated composite deck in Seattle, WA after 10 years
Year 10Slight early fade
MODEL SIMULATION
Seattle, WA · capped composite boards, south-facing, full sun
Color lossModerate
Surface wearMinimal
Mildew / rotModerate
Fails first hereShaded boards (surface mildew)

Check your city

Side by side

Year 10 in four climates

Seattle, WA · Cool & damp

Composite deck in Seattle after 10 years (simulation)
Composite deck25–33 yrs expected
Pressure-treated deck in Seattle after 10 years (simulation)
Pressure-treated deck12–15 yrs expected
Cedar deck in Seattle after 10 years (simulation)
Cedar deck15–19 yrs expected

Phoenix, AZ · Hot & dry

Composite deck in Phoenix after 10 years (simulation)
Composite deck22–28 yrs expected
Pressure-treated deck in Phoenix after 10 years (simulation)
Pressure-treated deck11–15 yrs expected
Cedar deck in Phoenix after 10 years (simulation)
Cedar deck18–24 yrs expected

Miami, FL · Hot & humid

Composite deck in Miami after 10 years (simulation)
Composite deck22–29 yrs expected
Pressure-treated deck in Miami after 10 years (simulation)
Pressure-treated deck9–11 yrs expected
Cedar deck in Miami after 10 years (simulation)
Cedar deck9–12 yrs expected

Minneapolis, MN · Mixed

Composite deck in Minneapolis after 10 years (simulation)
Composite deck25–32 yrs expected
Pressure-treated deck in Minneapolis after 10 years (simulation)
Pressure-treated deck11–14 yrs expected
Cedar deck in Minneapolis after 10 years (simulation)
Cedar deck15–19 yrs expected

Every city

Expected life by city

Sorted by how much longer the composite deck lasts. Model estimates from 1991–2020 NOAA normals.

CityComposite deckPressure-treated deck (unsealed)Cedar deck (untreated)DifferenceMain threat to pressure-treated deck
Atlanta, GA24–31 yrs9–12 yrs12–15 yrs+17.0 yrsMoisture & decay
Denver, CO23–30 yrs9–11 yrs14–19 yrs+16.5 yrsFreeze–thaw
Mobile, AL23–30 yrs9–11 yrs9–12 yrs+16.5 yrsMoisture & decay
Buffalo, NY25–33 yrs11–14 yrs14–18 yrs+16.5 yrsFreeze–thaw
Charleston, SC24–31 yrs10–13 yrs13–16 yrs+16.0 yrsMoisture & decay
Nashville, TN24–31 yrs10–13 yrs12–16 yrs+16.0 yrsMoisture & decay
Chicago, IL25–32 yrs11–14 yrs14–18 yrs+16.0 yrsFreeze–thaw
Minneapolis, MN25–32 yrs11–14 yrs15–19 yrs+16.0 yrsFreeze–thaw
New York, NY25–32 yrs11–14 yrs14–18 yrs+16.0 yrsMoisture & decay
Boston, MA25–32 yrs11–14 yrs15–19 yrs+16.0 yrsFreeze–thaw
Seattle, WA25–33 yrs12–15 yrs15–19 yrs+15.5 yrsMoisture & decay
Portland, OR25–32 yrs11–15 yrs15–19 yrs+15.5 yrsMoisture & decay
New Orleans, LA23–29 yrs9–12 yrs10–13 yrs+15.5 yrsSun & UV
Miami, FL22–29 yrs9–11 yrs9–12 yrs+15.5 yrsSun & UV
Tampa, FL22–29 yrs9–11 yrs10–13 yrs+15.5 yrsSun & UV
Albuquerque, NM22–29 yrs9–12 yrs16–20 yrs+15.0 yrsSun & UV
Salt Lake City, UT23–30 yrs10–13 yrs16–21 yrs+15.0 yrsFreeze–thaw
Houston, TX23–30 yrs10–13 yrs12–15 yrs+15.0 yrsSun & UV
San Francisco, CA24–31 yrs12–15 yrs17–22 yrs+14.0 yrsSun & UV
San Diego, CA24–31 yrs12–15 yrs18–24 yrs+14.0 yrsSun & UV
Dallas, TX23–30 yrs11–14 yrs15–19 yrs+14.0 yrsSun & UV
Austin, TX22–29 yrs10–13 yrs14–19 yrs+14.0 yrsSun & UV
Los Angeles, CA23–30 yrs12–15 yrs18–24 yrs+13.0 yrsSun & UV
Phoenix, AZ22–28 yrs11–15 yrs18–24 yrs+12.0 yrsSun & UV
Las Vegas, NV22–29 yrs12–15 yrs19–25 yrs+12.0 yrsSun & UV

“Difference” = midpoint for the composite deck minus midpoint for the pressure-treated deck. Methodology.

Upkeep

What each one needs

Questions people ask

Which lasts longer, a composite deck or a pressure-treated deck?

A composite deck, in 25 of the 25 cities we model. Typical national ranges are 25–30 years for a composite deck and 10–15 years for a pressure-treated deck; local climate moves both. Sealing wood every 2–3 years adds roughly a third to its life in our model.

Is a composite deck better than a pressure-treated deck in damp, rainy climates?

In the 7 cities where moisture and decay is the main threat to a pressure-treated deck (for example Atlanta, Mobile, Charleston, Nashville), our model gives the composite deck 16 years more on average.

Is a composite deck better than a pressure-treated deck in hot, sunny climates?

In the 12 cities where sun and UV is the main threat to a pressure-treated deck (for example New Orleans, Miami, Tampa, Albuquerque), our model gives the composite deck 14 years more on average.

Is a composite deck better than a pressure-treated deck in cold climates with many freeze–thaw days?

In the 6 cities where freeze–thaw is the main threat to a pressure-treated deck (for example Denver, Buffalo, Chicago, Minneapolis), our model gives the composite deck 16 years more on average.

What upkeep does each need?

Composite deck: no sealing; wash in spring and fall to keep mildew off shaded areas. Pressure-treated deck: clean and seal every 2–3 years in a dry spell; check board ends and joists each spring. Cedar deck: clean and seal every 2–3 years in a dry spell; check board ends and joists each spring.

More comparisons

Cedar vs pressure-treated deck →Vinyl vs wood fence →How long does a composite deck last? →How long does a pressure-treated deck last? →How long does a cedar deck last? →

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