Cleaning the deck before you oil will give your deck a nicer, more consistent finish. When you’ve had a deck for a few months, you will notice the colour start to fade and the finish look less lustrous and fresh. This kind of weathering is natural, and is all part of owning a deck. Eventually, it will come time to restore the finish – usually once every six to twelve months or so is fine, depending on what you used to seal the deck with in the first place and how much exposure to the elements it’s had. To make sure your efforts are truly effective, it’s important that you thoroughly clean the deck before you start.
How to clean a deck
To clean your timber deck, you don’t necessarily have to spend lots of money on special deck cleaning detergents. The active ingredient in most of these cleaners is sodium percarbonate, and it has plenty of other household applications – including in Napisan.
Add about 2 cups of Napisan (or a generic alternative that contains sodium percarbonate) to half a bucket of hot water, and you have a great solution for cleaning the deck with. Purchase a stiff bristled decking brush from a hardware store and give the boards a light scrub while applying the cleaner.
Leave the solution to sit on the deck for about 15 minutes or so, then add a little more to wet the boards again and then give it a really good brush down. Rinse it off thoroughly and allow it to dry for a day or two, depending on the weather. Doing this will strip out any of the old oil which may have gotten gluggy with dust and debris, and will restore colour to the wood.
How to oil a deck
Now it’s time to reapply the decking oil. You will need a tin of the decking oil you want to use, a decking brush and pole extension, a paint tray and a rag with some turps to clean up any messes or spills. Ensure the oil has been thoroughly stirred before using it, as you want to make sure the pigment has been properly mixed in.
The idea is to run as far along a single board as you can without touching any of the other boards. Only when you’ve finished one row should you start to move on across the deck. Applicators should be able to cover four boards at a time, so you can do this but you will need to concentrate on coating each board evenly. Long, continuous strokes with sufficient oil to soak into the wood will give you the best results.
If this is your first time, try and test the decking oil on an offcut to see how much oil to apply to soak into the wood, and to get an idea of how long it takes to dry. The directions on the tin should give you an indication of drying time and when to apply the second coat. Use less oil in the second coat than the first, as the wood will not absorb as much of it and it may pool on the surface and become sticky. Use a rag with turps to clean up any marks or spills; the turps thins out the oil.
When to oil a new deck
Decks made with fresh timber should ideally be left for two or three months before they’re oiled or stained, to allow the sun and rain to help tannins leach out of them.
Some decking experts suggest that this process can be sped up by washing the deck with a sodium percarbonate solution (as discussed above). If you’re not sure about when to oil your new deck, consult the manufacturer or installer.