We put down a trex deck on east side of our home with lots of shade 3 years ago. No problems with mold until we had a very wet spring and summer in minnesota this year. I expected to have to wash and maintain this low maintenance deck. We had lots of mold staining everywhere on deck. After tring Behr deck mold and remover with no luck I was extremely unhappy. Tried Simplying Green full strength with no luck. After pulling out my hair and complaining to my husband about why he wanted composite instead of wood I told him I would have been better off spending 2 days staining a real wood deck. After lots of reading on various threads on composite decking problems and trex websites on how to clean it,I finally found a product that working amazing! I used Mold Armour ez deck wash from Home Depot. I know the product contains a bleach solution but it worked in a matter of min. I did wet down the surrounding areas with a water hose including the railings and grass. Wet down the deck boards first before applying the product with a soft brush in an ice cream pail. No scrubbing was required but I had control with application by this method. I did small section at a time and rinsed off after only 5 min or so. You can see the product work! Be careful not to let solution on boards to long because it does contain bleach and bleach will fade anything it comes in contact with. I did this project on July 4 and want to see how long mold stays away. I plan on buying a more eco friendly product in future like Corte Clean but didnlt try it this time because no stores in our area carry it and it is quite expensive. You also have to watch expiration date and have to buy it on line. Has anyone had luck with this product with mold spots and how long does the mold stay away with Corte Clean or Mold Armour? By the way my deck looks amazing and has no structure problems like some I have been hearing about. My husband built deck himself and followed all the proper guidllines to install. We also used hidden fastener system for instalation and used proper support system underneath. We have the saddle color with accents brand. Hopefully the mold issue will be a controllable one since we plan on staying ahead of it this time and not wait so long to wash it. We also had alot of snow this winter and I didnt always get out there to promply to remove snow. Let me know if you have had better luck with other products as I dont want to use a product so often that contains bleaching agents. Still wish my husband would have agreed with me to use cedar but I lost the battle and had to settle for composite. I keep telling him I told you so about composite and I am stuck with an $8,000 deck that is not low maintenance. I appreciate any feedback on a sealer or something to put down so i only have to wash deck to maintain and keep mold spots at bay. Any luck with sealers or stains?

Wow. That is a mess. You have your work cut out for you. If you were going to use a semi transparent sealer of a different color you would positively have to strip that deck with something much stronger than RAD. If yu are okay with blotchiness (it may not even be too bad if you use a Cabot's decking stain). Back to the prep.. There is so much mold and it is so deeply ingrained you are going to have to let the RAD dwell for about 45 minutes and keep the wood saturated with cleaner the entire time. This will remove a decent portion of the sealer that is on there and make sure the mold spores are gone. Make sure you neutralize/brighten right away while the deck is still wet. Re-rinse. Let dry and apply Cabot's oil based penetrating deckin stain. It is a semi-transparent but it is opaque. Seacoast gray should cover the deck well and make it look pretty sweet.

I built a gray Trex deck four years ago that has been great. It gets no hotter than wood or concrete out in the sun. I have cleaned mine with a water, bleach, Jomas solution once which brightened it up. I do blow it off every morning. I don't drag anything across it cause it is somewhat soft. I don't drink cranberry juice while on it. I don't get grease around it. I treat it with respect and it treats me good.....no splinters, no twisting, no cracking, no rotting, and oh yes, NEVER any sealing, restaining. Here is a link that might be useful:

I will be replacing my wood deck either next summer or the summer after. Did a lot of reading on the different decking forums. Because I live in the ND/MN area, I need something that can withstand wide fluctuations in temperature. I will be going synthetic for ease of maintenance. Seems that the primary synthetic brands that receive the highest marks are Azek and Timbertech. The least maintenance is poly instead of composite but there are drawbacks - some creaking sounds and it is hot to walk upon. Ipe wood was the best to use if you want wood. It's a Brazilian hardwood, and costs more than cedar or pretreated wood. No one on the decking forum liked Trex. However, my carpenter brother-in-law is planning to use Trex when he replaces his deck. He likes Trex, but says that there are different levels of quality of Trex. Don't buy from big box stores because those are lower-quality "seconds." I'm having my front steps replaced in the next few days with Timbertech XLM, so I'll have an idea if I will like the 100% poly before I do a whole deck with it. So, there's my 4 cents. :-)