Cleaning out your wooden deck regularly is very important, especially as the end of the year approaches. The frigid weather of the winter months tends to threaten even the hardiest of woods with the growth of mold, mildew, and moss that will leave your deck in pretty bad shape. 


After all, you wouldn’t want to be greeted by a deck in disrepair when the spring thaw comes around. 

To properly clean out your deck, you will need the right selection of tools and chemicals for the job. While there are many such substances in the market to choose from, this article will be focusing on sodium metasilicate.

What is Sodium Metasilicate?

Now, we know that most of the people reading this are neither well-versed nor interested in chemistry, so we’ll try to explain this as simply as we can. 

Sodium metasilicate is a cleaning agent that can be used on its own as a cleaner for wood and metal and as an ingredient for other products like soaps and detergents. 

Chemically speaking, sodium metasilicate is known as an alkali salt, which gives it great stain lifting properties and the ability to kill off mold, moss, and other organic growths on your wood. 

Sodium metasilicate, if mixed with a high enough concentration, could also be used to strip wooden decks to prepare them for their new coat of paint, varnish, or sealer.

How to Use Sodium Metasilicate

Since sodium metasilicate is our primary cleaning chemical, it is most effective when used on the deck after several steps of preparation. We’ll go through the entire deck cleaning process to make sure you’re up to speed.

Deck Cleaning

Before anything else, you’re going to want to make sure your wooden deck is completely clear of any furniture and ornaments. Your next step would be to clean out the surface layer of dirt with water, either from your garden hose or pressure washer set at low to medium pressure.

Once your deck has been prepped, it’s time to break out your cleaning formula. Sodium metasilicate is typically sold in its powdered form, so you will need to make your cleaning formula yourself. 

Don’t worry, though, as the formula is pretty simple: just mix anywhere between ¼ cup to a whole cup of sodium metasilicate with 1 gallon of water. Of course, using more sodium metasilicate here will make the cleaning action stronger, so test a more dilute solution on an inconspicuous area of your deck to find out if you need to increase the concentration or not.

The next step is just a matter of doing the actual cleaning. You can use whatever cleaning tools and methods you like here.

While cleaning your deck with sodium metasilicate, there are a few things you should probably keep in mind. For one, this chemical is a serious irritant for the eyes (and the skin at higher concentrations), so wear protective gear to avoid this while cleaning.

We mentioned previously that sodium metasilicate can take out moss and mold from wood, but this also means that the chemical can eat away at the wood itself. 

To prevent this from happening, avoid using concentrations higher than what is instructed and make sure to keep the wood wet while working with the cleaner. 

Deck Stripping

We also mentioned earlier that you can use sodium metasilicate to strip sealing layers from your deck to prepare the wood for refinishing — an essential part of winter deck preparation. 

To do this, you will need to use a relatively higher concentration of the sodium metasilicate in your cleaning solution. All you need to do then is to follow the cleaning steps up to applying the cleaner to the wood, then leaving the cleaner there for about an hour.

As you wait, the strong alkaline characteristic of the sodium metasilicate will eat away at any finish that the wood has. After this, simply rinse away the cleaner, check to see any remaining finish on the wood, then spot clean as necessary to return the wood back to its raw, unfinished state. 

Sodium Metasilicate vs. Other Wood Cleaners

While sodium metasilicate is quite a capable wood cleaning chemical in its own right, it is by no means the single best deck cleaner on the market. 

There are many other options that all fall under the umbrella of “wood cleaner” but actually have their own pros and cons attached to them. We’ve listed a few of the most notable examples below. 

Oxalic Acid

Oxalic acid is an organic cleaning chemical that is known for its ability to brighten raw wood. This unique quality makes it an excellent bleaching chemical that can help restore a wooden deck to its former vibrance compared to sodium metasilicate and other wood cleaners. 

As its name suggests, this chemical is an acid, which means that it is especially useful for neutralizing the pH of wood after it has been cleaned with an alkali cleaner like — you guessed it — sodium metasilicate. For this reason, oxalic acid is typically used after stripping the wood finish to prepare the wood for the new one. 

Sodium Hydroxide

Sodium hydroxide is a cleaning chemical that most people probably already know by two other names in particular, namely lye, caustic soda, and common drain cleaner

If you have already worked with this chemical before, you will know that sodium hydroxide is a very powerful and corrosive substance that can eat away at stains that most commonly-available cleaners can’t. 

Compared to sodium metasilicate, the highly corrosive quality of sodium hydroxide makes it a much stronger stripping chemical, which makes it recommended for thicker wood finishes or if you just want to get the job done a bit more quickly.

However, this corrosive quality also makes sodium hydroxide unwieldy to use as a wood cleaner, as it can quickly eat away at the wood if it is left unchecked. For this reason, sodium metasilicate is preferred as a general cleaner. 

Editorial Contributors
Matt Greenfield

Matt Greenfield

Matt Greenfield is an experienced writer specializing in home improvement topics. He has a passion for educating and empowering homeowners to make informed decisions about their properties. Matt's writing focuses on a range of topics, including windows, flooring, HVAC, and construction materials. With a background in construction and home renovation, Matt is well-versed in the latest trends and techniques in the industry. His articles offer practical advice and expert insights that help readers tackle their home improvement projects with confidence. Whether you're a DIY enthusiast or a seasoned professional, Matt's writing is sure to provide valuable guidance and inspiration.

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