Pressure Treated Wood Decks on Long Island: Pros, Cons & Cost

What Pressure-Treated Wood Actually Is

Pressure-treated lumber is standard dimensional lumber — typically Southern Yellow Pine — that has been impregnated with chemical preservatives under pressure. The treatment protects the wood from rot, fungal decay, and insect damage. It's been the default material for deck framing and decking boards on Long Island for decades, and for good reason: it works, it's affordable, and it's available at every lumber yard from Riverhead to Valley Stream.

The chemicals used in modern pressure-treated lumber have changed significantly over the years. The older CCA (chromated copper arsenate) formulation was phased out for residential use in 2003 due to arsenic content concerns. Modern pressure-treated wood uses ACQ (alkaline copper quaternary), CA (copper azole), or similar copper-based treatments that are considered safe for residential applications, including around children and pets once dry. If you have an older deck — pre-2004 — that may use legacy CCA treatment, check with your contractor about replacement options.

For deck construction on Long Island today, pressure-treated lumber serves two roles: almost all contractors use it for the structural substructure (posts, beams, joists, ledger) regardless of what decking material goes on top; and some homeowners still choose it for the decking boards themselves as the most budget-friendly option.

Honest Pros and Cons for Long Island Homeowners

Pros of pressure-treated decking on Long Island:

Cost is the primary advantage. A 400 square foot pressure-treated deck on Long Island typically runs $14,000–$20,000 all-in, compared to $20,000–$30,000 for composite. If budget is the primary constraint and you're comfortable with maintenance, pressure-treated is a legitimate choice. It's also widely available — supply chain issues that sometimes affect composite products don't affect pressure-treated lumber. And if a board gets damaged, replacement is straightforward and inexpensive.

Pressure-treated wood also holds screws and fasteners naturally, accepts stain and paint well when properly prepared, and has a natural appearance that some homeowners genuinely prefer to the manufactured look of composite.

Cons of pressure-treated decking on Long Island:

Maintenance is the major drawback. Pressure-treated decking on Long Island needs to be cleaned, sanded (if staining), and sealed or stained every 1–3 years depending on exposure. In coastal communities, every 1–2 years is realistic. Skipping maintenance leads to graying, cracking, splinting, and eventually rot. Many Long Island homeowners who chose pressure-treated initially come back to us 10–15 years later to replace it with composite, having grown tired of the maintenance cycle.

New pressure-treated lumber must also dry out before it can be properly finished — sometimes 6 months or more depending on moisture content. This means the deck often looks rough and unfinished during its first full season. Finally, pressure-treated wood is heavier and harder to work with than composite, and the chemicals require that construction crews wear protective gear and dispose of waste properly.

For most Long Island homeowners planning to stay in their homes 10+ years and value low-maintenance outdoor living, composite is worth the premium. For a rental property, a first deck on a tight budget, or a homeowner who genuinely enjoys the maintenance process, pressure-treated is still a valid choice.