Decking · Cold, hard freeze–thaw
How long does a pressure-treated deck last in Salt Lake City, UT?
In Salt Lake City, freeze–thaw is the defining stress: about 91 days a year cross the freezing point (#2 of 25 cities we cover). Water in checks and fastener holes freezes and expands, so splits widen and fasteners loosen faster than sun or rot alone would explain. Model estimate: 10–13 years unsealed, 14–18 years sealed on schedule.
Storyboard
20 years in Salt Lake City, unsealed
Salt Lake City’s wear fingerprint
Each bar is scaled to the highest of the 25 cities we cover; the black line marks the median.
NOAA station SALT LAKE CITY INTL AP (USW00024127, 6.4 km away), 1991–2020 normals · humidity & UV: NASA POWER.
What fails first here
- 1Checks, splits and warpingAbout 91 freeze–thaw days a year work water into cracks and pry them open.
- 2Sun bleaching & raised grainSurface fibers break down under strong sun and wash away, leaving a pale, fuzzy texture.
- 3Mildew & algaeMostly a shady-corner issue here: 92 rainy days a year is moderate, but sun dries boards between storms.
- 4GrayingCosmetic, and fast: our model has the surface fully silver by year 2. Not damage on its own, but it means the protective surface is gone.
Upkeep
Salt Lake City 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.
Same city, other materials
How the alternatives age in Salt Lake City
Pin-ready
Save it for when you build.
The 20-year storyboard as a tall pin, linking back to this page.
Pressure-treated decks in similar climates
Denver, CO
Albuquerque, NM
Nashville, TN
Atlanta, GA
Dallas, TX…and in very different ones
Miami, FL
Tampa, FL
New Orleans, LAQuestions Salt Lake City owners ask
How long does a pressure-treated deck last in Salt Lake City?
Our model puts it at 10–13 years unsealed and 14–18 years if it is sealed every 2–3 years. The national typical range is 10–15 yrs; Salt Lake City’s freeze–thaw profile is why the local number differs.
When is the best time to seal a pressure-treated deck in Salt Lake City?
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 Salt Lake City?
Our model gives an unsealed pressure-treated deck 10–13 years here and untreated cedar 16–21 years. Where rot is slow, cedar’s stability wins: treated pine checks and warps faster in sun and frost.
Why does wood turn gray or black in Salt Lake City?
Graying is UV plus weathering of the surface; black spots are usually mildew or algae feeding on that grayed layer in damp weather, not rot. A cleaner and a dry-season seal stop it.
Model simulation, not a guarantee: south-facing, full sun, no shade or ground-contact surprises. How it works.