The frequency of staining a pressure-treated deck depends on several factors, including the type of wood, the climate in your area, and the level of wear and tear your deck experiences. Here are some general guidelines to help you decide how often you should stain your pressure-treated deck:

1. Type of Wood: Pressure-treated wood is treated with chemicals to resist decay and insects. The type of treatment and the specific wood species can affect how often you need to stain. Some pressure-treated woods are more resistant to weathering and might require staining less frequently.
2. Climate: Decks in regions with harsh weather conditions, such as intense sunlight, heavy rain, and extreme temperature fluctuations, may require more frequent staining. UV rays from the sun can fade the color and degrade the wood's surface.
3. Deck Usage: How often you use your deck and the type of activities that take place on it can impact the wear and tear. Decks that experience high foot traffic, outdoor cooking, and frequent gatherings might need more regular maintenance.
4. Stain Quality: The quality of the stain you use can affect how long it lasts. Higher-quality stains tend to offer better protection and longevity.
5. Previous Maintenance: If you've been maintaining your deck regularly and it's in good condition, you might not need to stain it as frequently. Regular cleaning and maintenance can extend the life of the stain.

In general, a pressure-treated deck might need to be stained every 1 to 3 years. However, it's important to monitor the condition of your deck to determine the right timing. Here are some signs that your deck might need staining:

• Fading Color: If the color of the stain has faded significantly, it's time to consider restaining.
• Water Absorption: If water is no longer beading on the surface of the wood and instead is being absorbed, it's a sign that the protective layer is wearing off.
• Visible Wear: If you see signs of cracking, splintering, or peeling on the wood's surface, it's time to address those issues and possibly restain.
• Loss of Protection: If the wood's appearance looks dull and lacks the luster it had after the last staining, it's likely time for a new coat.

Before restaining, make sure to thoroughly clean your deck and perform any necessary repairs. Sanding the surface can also help the new stain adhere better. Always follow the manufacturer's guidelines for the stain application process.

Remember that these are general guidelines, and your specific situation may vary. Regular inspections and maintenance will help you determine the optimal timing for staining your pressure-treated deck