Every homeowner rebuilding a deck asks the same question eventually: composite or real wood? The honest answer is that both are reasonable choices — the right one depends on how long you plan to own the house, how much maintenance you're willing to do, and how much the upfront cost matters versus the cost over time. Here's how they actually compare under Bay Area conditions specifically, not generic national averages.
Upfront cost vs. cost over 15 years
Composite decking material typically runs 1.5–2x the cost of pressure-treated pine and about 1.2–1.5x the cost of redwood, installed. That's the number most people fixate on. But it's the wrong number to compare in isolation.
Over a 15-year window, a wood deck needs stripping and resealing every 1–3 years depending on exposure (we cover the specifics of that in our deck resealing guide). At roughly $3–6 per square foot per resealing visit, that adds up to more than the composite premium paid upfront in most cases — sometimes significantly more, especially for decks in foggier neighborhoods that need sealing more often.
How each holds up to SF fog specifically
This is where local conditions actually change the math, and it's the part most national buying guides skip.
- Wood in fog-belt neighborhoods (Sunset, Richmond, Outer Parkside, coastal Pacifica) takes on moisture from fog daily, not just from rain. That accelerates the swell-shrink cycle that breaks down sealant and eventually opens the grain to rot. It's manageable with a disciplined resealing schedule, but it's a real, recurring cost and a real, recurring task on your calendar.
- Composite doesn't absorb moisture the same way, so fog exposure barely changes its maintenance needs. This is the single biggest reason we recommend composite for decks within a few blocks of the coast.
- Both materials need the substructure protected. Composite boards don't rot, but the wood framing underneath them still can if it's not flashed and ventilated properly. A composite deck built on a poorly protected frame is not actually a low-maintenance deck — it just hides the problem until it's serious.
What composite doesn't fix
Composite is genuinely lower-maintenance, but it's not maintenance-free, and it's worth knowing what it doesn't solve:
- It still needs periodic washing. Mildew and algae grow on composite in shaded, foggy spots just like anything else. It's easier to clean — usually a hose and mild soap — but it's not optional.
- Railings and trim are often still real wood unless you specifically spec composite or vinyl for those too. A lot of "composite decks" we get called out to still have wood railings that need staining.
- It gets hot. Darker composite colors can run noticeably hotter underfoot in direct sun than wood does — less of an issue in most SF microclimates, more relevant in sunnier East Bay and Peninsula yards.
When wood still makes sense
Composite isn't the right call for everyone. Real wood is usually the better choice when:
- You're doing a smaller repair or partial rebuild and want it to match existing wood decking
- The home has architectural character where a natural wood tone matters more than long-term maintenance
- Budget is tight upfront and you're comfortable with a resealing schedule
- You're planning to sell within a few years and want to match neighborhood norms rather than maximize your own long-term cost
We install and repair both, and we don't have a default answer we push on every job — it genuinely depends on your specific deck, exposure, and plans for the house. If you're deciding between a full rebuild in wood versus composite, that's worth a short in-person look before you commit, since the framing condition and sun/fog exposure of your specific yard usually matter more than the general pros and cons.