Decks, Patios, Porches and Docks - Necessary to seal after pressure washing?

I recently moved into a house that has a deck. The deck has a significant amount of mildew, as a lot of it is out of the sun. Some of the spots are like an ice-skating rink when wet. I spoke with the landlord and he said I can pressure wash it to make it less slick and brighten it up. He also informed me that the deck was sealed 2 years ago. I was planning on renting a 1700PSI electric pressure washer and cleaning it with just water, no chemicals. If I pressure wash it without chemicals or cleaning agents, does it have to be resealed? He's uinder the impression it shouldnt, but from the reading I've done it seems everyone re-seals after pressure washing. I dont know much about wood, but it's pressure treated lumber if that helps.

TIA,
Craig

The wood in your deck is slowly rotting - not that you're going to see it for many years, but all wood outside decays. If you seal the deck, it should last a few years longer, but might not be a difference you would see anytime soon. Sealing also gives you the ability to change the color, as many do not like the color of PT wood.

Welcome to the forums Craig

Deck sealers don't typically last longer than 2-3 yrs. Pressure washing the deck will remove some of the remaining sealer. It would be best to reseal the deck.

Thanks for the info. I've learned there's a board for everything these days.

I tried using the search feature but didnt quite find what I was looking for. I dont plan on being in the house for more than a year or two, so I'm just going to power wash it. I'll let the landlord worry about re-sealing it later. I just wanted to confirm that I wouldnt wake up the next day to a collapsed or destroyed deck. Thanks again...

Landlord? You rent? Forget about it, I wouldn't seal it either.

I'd talk to the landlord some more before I did ANYTHING. Let him pay the rental on the pressure washer. If he wants the deck sealed afterwards (which it should be), let him buy the stain/sealer. If you do the work, he should be willing to compensate you for your time as well.

I talked to him and he said I could pressure wash it. He leaned toward the fact that as long as I didnt use any chemicals, he wouldnt need to seal it right away. That's why I'm not too concerned. I tossed the idea of having him pay for the pressure washer, but I never persued it. It's not a necessity, so I dont know how that'd fly. Although I guess I could slip on the wet mildew and have him pay for everything. Right now I'm just trying to get my roommate to split the pressure washer with me. It's on $35 for 4 hours, so it's not really a bank breaker.