Had a new PT deck installed last spring. We do a ton of container gardening and were told to try and keep soil/leaves from accumulating on the deck since there could be mold problems, so we've been doing our best. In late summer we cleaned and sealed it using Sikkens SRD semi-transparent. Looked fine at that point.

Over the past month, the leaves have been raining down and it was hard to keep up with sweeping them off. Plus we were away for a week during the worst of it. After getting most of them off, the deck was REALLY gray and dingy, so today I went out and used our low power electric pressure washer to see how that would do. Got perhaps 80% of the dirt off but some of the stains are a bit more persistent. A couple of questions given that this will be a yearly problem:

1) If I pressure wash the rest of it before winter to try and remove at least most of the dirt, will that "destroy" the sealant that was put on a few months ago?

2) If using the electric PW is safe, are there soaps or cleaners I can use in conjunction with that to get the rest of the dirt off? Since we have a lot of landscaping near/under the deck I doubt we'd want to use something like bleach.

3) If the solution is using a high powered PW in the spring, I assume we'd need to reapply the sealant. I was hoping to have to do this perhaps every other year, but doing it only on the horizontal surfaces where it's now dirtiest wouldn't be a horrible chore.

Larry