How to clean mould off teak outdoor furniture and decks
Everyone loves spending time outdoors, especially in our own yards – sitting on the deck with a glass of wine, enjoying the cool evening air… But sometimes, this precious time can be ruined by the presence of mould. So you find yourself wondering how to clean mould off teak outdoor furniture…
Mould can grow in many places. However, it is especially annoying when it appears on our outdoor furniture or desks, particularly those made of lovely wood like teak or spotted gum. So if you’ve found mould or mildew growing on your teak outdoor furniture and decks, here’s how to handle it and get your outdoor furniture and decking looking gorgeous in no time.
Frequently asked questions about teak outdoor furniture and decks
Why does my outdoor furniture grow mould?
Teak is one of the most mould and mildew-resistant woods out there, making it ideal for outdoor furniture and decking. However, because teak outdoor furniture is consistently exposed to the changes in the weather, such as the cold, humidity and wetness, it can often still be an efficient environment for bacteria and mildew to grow.
The benefit of using teak is that due to the density of the wood and the natural oils and resins within it, it is relatively resistant to any mould growth, particularly within the wood. Most mould or mildew will simply grow on the surface, as it is often unable to penetrate any further.
Can I pressure wash teak furniture or decks?
Generally, it is not advised to pressure wash your teak furniture, however depending on what timber you have in the deck, decks can be pressure washed. Pressure washing teak furniture or teak of any kind can cause the surface of the wood to become bumpy and pitted and can strip away the wood's natural oils. (We recommend water-based products, not oil based)
This damage causes the wood to age prematurely and will remove the smooth finish that is characteristic of teak furnishings.
When should I clean my teak furniture and deck?
Teak is pretty resistant to most things, so you don't necessarily have to clean your teak decking or outdoor furniture very often. However, if you notice any dirt, grime or mould beginning to appear, that is a sign that you should wash your decking or furniture.
Likewise, if you spill something on the decking or your teak table, gently washing that away will help to maintain your wood.
However, if you have oiled your teak, you will need to oil it continuously every six to twelve months. When oiling the wood, it is advisable to clean it first gently.
How to clean your teak outdoor furniture and decking
When it comes to cleaning mould or mildew off of your teak outdoor furniture and decking, there are a few different approaches you can take, depending on what products you want to use. Or alternatively, you can choose to hire professionals to take care of your outdoor furniture and decking for you.
It is paramount when cleaning teak to remember to be gentle. The wood has natural oils that help protect it from weathering and cleaning too vigorously, or the wrong products can strip these oils away.
Using a commercial cleaner
Perhaps the easiest option for cleaning mould and mildew off of teak is by using a commercial teak cleaner. We typically use Golden Care Teak Cleaner that’s available online and in high-end outdoor furniture stores. If that’s not dealing with it, your best bet is to buy antimicrobial spray. Many other brands/products are available to buy in gardening stores and online and are formulated to work on teak. If you’re using a commercial teak cleaner, you can clean the mould away by following these instructions:
• Dust and brush your teak gently to remove any cobwebs, leaves, dirt or debris.
• Moisten your teak with warm water.
• Follow any pre-use instructions on your commercial cleaner. These often involve shaking the bottle before use.
• Apply your teak cleaner to the wood, ensuring that you cover any areas with mould or mildew.
• Using a soft brush - nylon brushes are ideal - scrub the cleaner into the wood gently, following the grain of the wood (if you’re unsure, the lines on the wood point in the direction of the grain).
• Leave to soak for a few minutes, no longer than 20 (it may well provide a time on the cleaner).
• Rinse the cleaner off with a hose on a reasonably low pressure.
• Leave to dry.
Using homemade cleaners
If you search for homemade cleaner recipes to remove mould and mildew from teak wood, you will be met with a plethora of varied responses. However, there are three main recipes for cleaners that are easy to make at home, and which one you use depends on you.
Mouldy Teak cleaned and coated with Golden care instant grey
Detergent-based cleaner
This is the gentlest homemade cleaner and ideal for any tiny mould or mildew growth spots on your teak outdoor furniture and decking. To make the cleaner, mix 1 cup (or 236 ml) of liquid laundry detergent with 1 gallon (4.5 litres) of warm water.
You can, if there is a lot of mould on the wood, add 1 cup (236 ml) of bleach to this. Once made, follow these instructions:
• Dust and brush your teak gently to remove any cobwebs, leaves, dirt or debris
• Moisten your furniture with warm water
• Apply the detergent-based cleaner with a soft sponge
• Soak for 5 minutes, and absolutely no longer
• Rinse with a hose or warm water
• Leave to dry
TSP-based cleaner
For specifically targeting mildew, you might want to make a TSP-based cleaner. However, this is slightly harsher than the detergent-based cleaner and may be harder to source the ingredients for.
To make the cleaner, mix 1 cup (236 ml) of trisodium phosphate (TSP) with 1 cup (236 ml) of oxygen or chlorine-free bleach and 2 gallons (9 litres) of warm water. To use the cleaning solution, follow these instructions:
• Dust and brush your teak gently to remove any cobwebs, leaves, dirt or debris
• Moisten your furniture or decking with warm water
• Apply the detergent to the targeted areas
• Leave to sit for about 30 seconds
• Rinse with a hose or warm water
• Leave to dry
Vinegar-based cleaner
The most natural cleaning solution you can make at home for use on your teak is a vinegar and warm water solution. Simply add 1 cup (236 ml) of white vinegar to a gallon (4.5 litres) of warm water. Once mixed, use the following instructions:
• Dust and brush your teak gently to remove any cobwebs, leaves, dirt or debris
• Moisten your furniture or decking with warm water
• Wipe the vinegar solution onto the wood using a soft cloth or brush
• Let the solution soak for about 15 minutes
• Remove solution using a clean sponge or cloth, in line with the grain
• Rinse the wood
How to decide on a cleaning product
It can be difficult to decide which products to use to clean your outdoor furniture with so many options. But there are differences between them; the bleach and TSP cleaners are more severe, and these may not be the best choice for damaged wood.
Likewise, using bleach in a homemade solution can be risky, as without diluting it correctly, it may leave blemishes on your wood.
If you're unsure whether you want to make your own cleaning solution, it may be worth shopping around for commercial teak cleaners or hiring experts to help you remove the mould and mildew from your outdoor teak furniture and decking.
Par Arnoldson, the founder of Fornya, is a Teak Maintenance Specialist based in Sydney, Australia.