That's an excellent question, and one that every park manager, community volunteer, or homeowner with a garden bench should ask. The short answer is: for optimal protection, you should stain or treat a wooden park bench every 1 to 3 years. However, the exact frequency isn't a one-size-fits-all rule. It depends heavily on several key factors.
First, consider your local climate. Benches in harsh, sunny climates with intense UV exposure or in regions with heavy rain, snow, and freeze-thaw cycles will need more frequent attention—likely every 1 to 2 years. In milder climates, you might stretch to every 2-3 years.
The type of wood and the current finish also play a huge role. Dense, naturally rot-resistant woods like cedar, redwood, or teak may last longer between treatments. A bench with a penetrating oil or stain needs reapplication when water no longer beads on the surface. A film-forming finish, like a solid-color stain or paint, needs redoing when it cracks, peels, or flakes.
Don't wait for obvious failure. The best practice is a simple annual inspection. Look for these signs:
* The wood appears gray, dry, or faded.
* Water soaks in immediately instead of beading up.
* You notice small cracks or splintering.
* The finish is visibly peeling or worn thin in high-use areas.
A consistent maintenance schedule is far easier and cheaper than replacing a rotted bench. A thorough cleaning with a wood cleaner and a fresh coat of a high-quality, UV-resistant stain or sealant will shield the wood from moisture, sun damage, and everyday wear. This not only preserves the bench's strength and safety but also maintains its aesthetic appeal for everyone to enjoy.
In summary, mark your calendar for an annual check. If it looks thirsty or worn, it's time for treatment. Staining every two years is a good average, but let the condition of the wood—not just the calendar—be your ultimate guide.