Almost every deck job ends with a few boards over. You order extra for the cuts and the wastage, the deck comes in a bit shorter than the plan, or someone changes their mind about the size halfway through. Then the job's done and there's a bundle of good decking sitting against the fence.
My husband's on the tools, so I've watched this happen plenty. Decking is not cheap timber. Leaving it out to grey off and cup is a waste of money that someone paid for. Here's what actually to do with it.
First, work out what you've got
Before you can do anything useful with leftover decking you need to know what it is. Buyers and re-users care about three things.
The species or material. Merbau, spotted gum, blackbutt and other hardwoods hold their value. Treated pine is cheaper but still worth something. Composite decking like the wood-plastic boards is its own category and people match brands, so note whose it is if you can.
The profile and size. Grooved or smooth face, the width (86mm and 135mm are common), and the board thickness. Two lots of merbau that look the same can be different widths, and a renovator finishing a deck needs the width that matches what's already down.
The length and quantity. Count the linear metres, not just the number of boards. "Six lengths of 5.4m spotted gum" tells a buyer far more than "some decking".
Two minutes with a tape and your phone camera and you've got everything you need to move it on.
Store it properly if you're keeping it
If you've got a reason to hang onto it, store it so it's still usable later. Hardwood decking moves a lot, and boards left in a leaning pile in the weather will cup, twist and split.
Keep it flat and off the ground. Stack it on bearers or a pallet so air can get underneath, put stickers (small offcuts) between the layers so air moves through, and keep it out of direct sun and off wet ground. Under cover is best. Get it flat and ventilated and it'll still be straight when you want it.
If you're not going to use it inside a few months, though, storing it is really just delaying the decision. Decking-grade timber sitting in a corner is money doing nothing.
Reuse ideas that are actually worth it
There's plenty you can build with a small amount of leftover decking without it turning into a project that costs more than it's worth. A step or two off an existing deck. A planter box or a raised garden edge. A simple bench seat. A bit of screening or a gate. Hardwood offcuts also make good stickers and packers for the next job, so keep a few short bits handy.
What's usually not worth it is trying to store enough for a "someday" deck that never gets built. If you've got real lengths left over, they're worth more to someone finishing a job now than they are aging in your shed.
Sell it or give it to someone finishing a job
This is where leftover decking is different from a lot of other offcuts. Good hardwood boards are wanted. Someone three suburbs over is a few lengths short of finishing their deck and does not want to buy a full pack to get them.
That's the whole reason I built Overrun. It's an Australian marketplace where tradies and renovators list surplus building materials instead of skipping them. Listing takes under a minute from your phone, the buyer collects and pays you directly, and Overrun never takes a commission on the sale. A photo, the species, the sizes and lengths, and your suburb is enough. If you'd rather just clear it, list it cheap or free and it'll go quicker.
Only building materials get listed, so it's people who actually want decking, not tyre-kickers.
Disposal is the last resort
If boards really are damaged or too short to be useful, get rid of them properly. Treated pine should never be burnt. The preservatives in it are not something you want in smoke or ash. Composite decking isn't timber and won't go through a green-waste stream. For both, your local transfer station or waste facility is the place to check what they'll take and how they want it sorted. Rules vary by council and site, so ring ahead rather than guessing.
But disposal should be the last option, not the first. Most leftover decking is too good and too valuable to be treating like rubbish.
Quick answers
Can you store decking timber outside? Yes, if you do it right. Stack it flat on bearers or a pallet, off the ground, with small offcuts between the layers so air can move through, and keep it out of direct sun and off wet ground. Under cover is best. A leaning pile in the weather will cup and twist.
Is second-hand decking worth selling? Hardwood decking like merbau and spotted gum holds real value, so yes. Someone finishing a deck often needs a few lengths and doesn't want to buy a whole pack. List the species, profile, widths and lengths and it usually moves fast.
Can you burn leftover treated pine? No. Treated pine contains timber preservatives and should never be burnt in an open fire, wood heater or burn-off. Check with your local transfer station or waste facility for the right way to dispose of it.