Cleaning your Wood Deck with W99

Posted by Michael Mankarious on 28th Jun 2018

Cleaning your Wood Deck with W99

If you've got a wood deck you know how much enjoyment it can bring during the summer months whether you're hanging out on it solo sipping some iced tea or spending time in the company of friends. What's not fun about having a deck is keeping it in good shape. 

Sure, we're here to show you how to keep your vehicle clean and well maintained, but it doesn't mean our products are restricted to vehicle detailing only.

Industry Cleaner W99 is one of those products in our lineup that is very versatile (Blitz APC is another fine example). 

One area where W99 is very good at is removing build up of paint, stain, algae and mold from surfaces such as concrete and wood. For this project, we used W99 to prepare the wood for a fresh restain. 

After a year of Texas sun, winter snow and ice and a year round dose of mold, this deck was in need of a good deep clean and a fresh coat of stain and sealer. 

We used a pressure washer to make cleaning fast, effective and easy. You can rent one from your favorite big box home store. The pressure washer that was used has a siphoning tube that can be inserted into a bottle of detergent - in our case, W99. It mixes the detergent (W99) with the water as it's being sprayed. If you're using a pressure washer, check to see if it has this feature. If not, prepare a solution of W99 and water in a mixture of 1:30-1:50.


What We Used:

  • Pressure Washer with detergent siphon attachment
  • 1 liter of nextzett W99
  • Bristle floor brush
  • Extension pole to attach to brush
  • Sherwin Williams Super Deck (natural)

First and foremost, make sure the surface you're working on is not in direct sunlight (avoid midday) and that the surface itself isn't hot. Otherwise the cleaning solution will dry too fast preventing it from working at its maximum capabilities.

Step 1

Remove any loose debris like leaves, accorns, and dirt from the deck with a broom or leaf blower.

Step 2

With your garden hose, rinse the deck with a jet of water and spray any surrounding plants and grass with water so that when the solution makes contact it will be diluted and won't harm the plants.

Spray water on the wood deck before cleaning

Step 3

Using the soap attachment on the pressure washer, apply W99 to the surface. Work in manageable sections otherwise the solution will dry by the time you get to the other parts of the deck.

Spray the deck with W99 using the detergent attachment on your pressure washer

If you're not using a pressure washer or you are and there's no detergent attachment, spray the solution of W99 and water (as directed above) on the surface with a spray bottle, brush, pump sprayer, etc.

After spraying, allow the solution to work for a few minutes. 

Step 4

Scrub the surface with a brush either made with fiber or nylon bristles. A nylon brush will be more aggressive and ideal for surfaces that are very dirty.

Scrub the wood deck with a brush to work the W99 detergent cleaner

Step 5

Powerwash the deck to remove the mold and mildew. For instructions on proper washing technique, check out the numerous videos on Youtube. In general, you'll want to use a tip that isn't too direct. For this project a tip with a 25 degree spray pattern was used. Use a 40 degree spray attachment for less aggressive cleaning but don't use an attachment less than 25 degrees or you'll damage the wood. While washing, you'll want to keep the wand moving and not staying in one place too long.

Powerwash the deck with a power washer

Before and after powerwashing deck - mold and mildew removed

Before and After Cleaning with W99


Wood deck before cleaning with nextzett W99


After cleaning the wood deck

Step 6

After cleaning, allow the surface to dry 24 hours before staining or applying deck paint.

Here's what our deck looks like after applying stain. No longer is it covered with build up of dirt and algae. The grain and color variations are now revealed. 

Deck after stain with Sherwin Williams Super Deck 

Wood deck after application of Super Deck stain by Sherwin Williams


In addition to cleaning decks, consider using W99 to clean siding and concrete. W99 will remove oil stains from concrete when applied in the same manner as used in this deck cleaning project.

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