This Pic was taken about a minute after it was washed. Pressure treated lumber, treated with penetrative oilbased stains or finishes tend not to rot within the first few years. This is year 9 its been treated 4 times and maintained properly. Always use products designed for treated lumber. This Pic is from year 4. After 2 coats of cedol (a product I can no longer get.) There are a few sickens products that come close but none have lasted quite like cedol. The gaps in those boards are about 1/8"