Checked a deck I built 4 seasons back in Tacoma and found soft spots already
I was in Tacoma last month to look at a fence for the same customer and walked out back to see how the deck I finished 4 seasons ago was holding up. Two boards near the west edge gave under my boot, right where the downspout dumps rain off the roof. Pulled one and the end grain was dark and crumbly, and the ledger flashing I fastened with 8d nails had pulled loose. Turns out the deck screws I used were the coated kind rated for treated wood, but the joist hangers were the cheap galvanized ones that eat into ACQ lumber. If you're building anywhere it rains 40 inches a year, spend the extra couple bucks on hot dip hardware, or you'll be back out there way sooner than you want. Anyone else up here seen joist hangers failing way too early on treated lumber?
Two boards out of the whole deck after 4 seasons in Tacoma rain sounds about right, not some big red flag. That spot by the downspout is the wettest corner of any deck, so of course the end grain goes first. Cheap galvanized hangers on ACQ will lose you some years, sure, but the flashing pulling loose is the bigger problem there, water got behind it. Hot dip is better money spent, just don't act like coated screws and standard hangers are junk everywhere or everyone would be rebuilding every 3 years.