How would YOU clean this composit decking? PICS

This stuff is old and full of algae…Im thinking a bleach solution, however…not sure the ratios and dwell time. Its trimmed out with natural wood and you can see the floor joists from the yard. Ive cleaned a couple of decks and I get streaking on the joists below the deck boards even when one of us is continually spraying the bottom down with water. Anyway, suggestions to avoid streaking on the underside of decks, and how to or ratios for this deck would be fantastic!

Thanks in advance!

Downstream your house wash (50% H20 and 50% 12.5 SH). Let it dwell for 10 minutes and hit with a 40 degree tip(we use our surface cleaner).

1 gallon 12.5, 3 gallons water 2 scoops simple cherry, slop it on with a brush, you shouldn’t have to scrub just get it on there. Let dwell a few minutes and spray off with a garden hose.

Where do you guys get the 12.5?

Pool supply companies often have it in sizes from 1 gal to 20 gal, where I am.

If I just brush it on and let it dwell wont I get streaking on the underside of the deck on the joists?? That is one of my main concerns,…when I get a deck high off the ground how do I prevent the streaking. I keep it wet but I still get the streaks :confused:

charge more and clean the underside?

Some composites react to house wash mix different than others. You need to be careful and find out the manufacture. I would start with a week mix and work up if necessary. Spray your mix on and brush than rinse.

Whats works out good for me is a house wash mix. Let it dwell for 10 to 15 min & i rinse off with my m jet head on a strong fan spray. Not everyrhing is going to come off. Explain to the H.O. that alge & dirt are deep in the fibers. Dont use pressure or you’ll destroy it. As far as the streaking wash the underside first. Charge more if need be.