Decks, Patios, Porches and Docks - Deck Wash?

I power wash my deck every other year & started it again today. I ran out of the deck wash I usually get at Home Depot to aid in power washing, but am wondering if it really does anything to help remove the stains? (I'm thinking that maybe I'll just use the power washer unless I can be convinced that the addition of a deck wash will make the deck look better &/or speed things up)

Deck washes clean the surface and bleach to remove mold, mildew and other discoloration. If all you have on your deck is soil, then power washing with plain water may be effective.

You report that you have been using deck wash every other year. How effective has it been for cleaning your deck? Do you have mold, mildew, or discoloration?

Yes I get all those problems but have heard the deck sealants only work for a few years anyway so I figure I'll need to power wash regularly anyway. I could do it every year but have found the staining/mildew isn't to bad after just one year. By the 2nd year it nededs to be power washed.

I just use bleach - get the deck wet with the hose, spray bleach on from a pump sprayer, scrub a little and then rinse off.

did you dilute the bleach, or use full strength in the sprayer?

NEVER USE STRAIGHT BLEACH!!!

Pure bleach destroys wood fibers. The bleach water solution should never be stronger than 50% bleach. It works best if you apply it to an already wet surface and rinse before it dries! If it needs more either scrub as Mitch said or retreat.

If you want to take stains out of old timber then there is nothing like oxalic acid it brings it up like new. it been quite a while since I used the stuff I used to be able to get it at the hard ware. Otherwise look it up on the web. And make sure you get safety directions with it.

Robbert

Most commercial deck washes contain oxygenating bleach. Check the labels and look for products that contain the highest percentage of sodium percarbonate (when this powder is mixed with water it becomes oxygen bleach). Many do not recommend the use of chlorine bleach or pressure washer on wood decks because of potential damage to grain. The more conservative approach is to wet the deck, apply the cleaner, let set 10 minutes and then hose off. Do not leave on for longer than manufacturer recommends. Thus, it may be necessary to do a section at a time. Oxygenating bleach will remove soil and mold and mildew. For tannin and iron stains, oxalic bleach can be used.

twelvepole,

I have a cedar deck that has a Sikkens SRD finish on it. The finish is about 18 months old and is due for a fresh coat. It has turned dark brown almost black, tannin?. Will an application of oxalic bleach alone prepare the cedar for a fresh coat of the stain? I would rather stay away from powerwashing it, I dont want the grain raised and I know powerwashing will do this.

thanks,

Tom

A pressure washer will not ruin the wood if used correctly but used incorrectly can!!! Cleaning your deck may bring back the color, if not use a wood/deck brightner which will. Both can be used with or without the use of a PW.

LI Tom, clean the deck first. An oxygenating bleach cleaner usually does the job. Then, if there are tannin stains, you can use the bleach. Many use power washers on decks. They watch the pressure and maintain the same distance between wand and deck to assure even application of pressure. If not used properly, the power washer can damage the surface.

Thanks for the replies. I do own a pressure washer and have use it in the past. I did a friends deck once and after about 10 minutes realized that I really didnt know what I was doing when it came to cleaning wood with it. That is why I am shying away from using it.

thanks

Tom