Ethically Kate: How can I get rid of mildew without using chemicals?

Cleaning products are often very expensive and arrive in thick packaging that could have easily been avoided. Photo / 123rf

OPINION

Q: Our timber deck is covered in slippery mildew. How can I clean it without using chemicals?

A: When you start searching for sustainable or natural deck cleaners, ads will quickly consume your social media feeds with “sustainable” products to solve all your mildew woes. Ignore those. Sure, some products will work well and may be less toxic for the environment surrounding your deck, but they’re often incredibly expensive and arrive in thick packaging that could have easily been avoided. Mildew can be removed with the most basic ingredients!

Before I describe simple, cost-effective and environmentally friendly solutions, let’s journey on a little tangent concerning the use of the word chemicals in your question. Chemical-free does not mean a product is sustainable, and a product that contains chemicals is not necessarily bad for the environment.

For example, water is a chemical. Chemicals are everywhere and are often helpful. Don’t worry, you’re not the only one to misuse this word, and I know what the intent of your question is. My reason for this wee tangent is to upskill you on spotting greenwashing. Now that you know “chemical-free” doesn’t hold any weight or make rational sense, you can avoid being sucked into sneaky marketing techniques.

The most common method involves sprinkling baking soda over the deck and leaving it for 30-60 minutes. Photo / 123rf

Jumping back to your slippery deck, there are two basic ingredients you can experiment with that you may already have in your house. Baking soda and vinegar. The most common method involves sprinkling baking soda over the deck and leaving it for 30-60 minutes. While you’re waiting, add a cup of white vinegar to 4 litres of warm water. Spray or pour this over the deck and get scrubbing.

Skipping the vinegar and just using baking soda can also work. Like I said … experiment! The ratios and ingredients that work best will depend on many things such as how long the mildew has been there, what type of timber your deck is made from, and if it’s mildew or mould.

Mildew is a surface fungus, often referred to as the early stage of mould. Mould generally grows deeper into the material, making it harder to remove.

Before you start sprinkling baking soda on your deck, it’s also important to do your own research that is relevant to the type of timber your deck is made from. Baking soda and vinegar are strong chemical compounds. If you have a coating on your deck, they may not only combat the mildew but also destroy the coating. Patch test first and stick to the recommended ratios. My final word of wisdom before you head to the bulk bin store with your refillable containers to buy vinegar and baking soda, is to stay safe. Even though baking soda and vinegar are safer to use than most fancy deck cleaners, scrub the deck wearing gloves and rinse your lovely mildew-free deck with water afterwards.