Key takeaways
- Four common failure modes: tarpaulins, bare concrete, exterior walls, and stacks too high for too long.
- Outdoor storage under a tarpaulin can be worse than open air, because it traps humidity against the board.
- The same accumulation can lose a grade or more over winter without doing any work in between.
- If you have no use for the boxes yourself, selling before winter often beats storing them through it.
A common pattern in the used box trade: an accumulation that would have graded well in autumn is a lower grade by spring. The boxes did no work in between. They sat somewhere, and where they sat did the damage.
The four ways winter storage goes wrong
1 · Outside, under a tarpaulin
The worst option available, and a common one. A tarpaulin keeps rain off and traps humidity underneath, producing a small, permanently damp microclimate around the board. Open-air storage on pallets is generally better, which is counterintuitive enough that people do not believe it until they have compared both.
2 · On the concrete
Slabs wick moisture continuously, particularly through winter temperature swings. The bottom course takes it up and, because the bottom edge is the structural part that matters most, that is exactly the wrong place to lose strength.
A pallet or slip sheet under every stack largely solves it and costs very little.
3 · Against an exterior wall
Condensation forms on the inside face of uninsulated exterior walls through winter. Boxes stacked flush against them get a damp stripe down one side that is invisible until you turn the stack round in spring. Leave a generous gap between stacks and exterior walls.
4 · Too high, too long
Creep is cumulative. A stack of flattened bundles that is fine at a moderate height for a few weeks can have permanent set in the bottom bundles if it is taller or stands for months, and those boxes will not square up properly again.
| Storage | Likely outcome by spring |
|---|---|
| Indoors, palletised, banded, moderate stack height | Little or no change |
| Indoors, on concrete, unbanded | Likely to drop a grade |
| Indoors, against an exterior wall | Likely to drop a grade |
| Outside, under a tarpaulin | Can drop several grades or be rejected |
| Outside, open air, on pallets | Likely to drop a grade or more |
What good storage looks like
- Flattened. It is the single biggest factor in how much space the accumulation takes and how well it keeps its shape.
- Banded in consistent lots, so nothing splays and counts stay verifiable.
- On pallets or slip sheets. Never directly on the slab.
- Under a roof, with a gap from exterior walls.
- A sensible stack height, and rotated if the accumulation will stand for more than a few months.
Or just sell them before winter
This is the alternative worth considering. Material sold while it is still in good condition is likely to be placed at the better end of its range, and a free, no-obligation quote request is a quick way to see what partner suppliers can offer.
The same material sold in spring, after a winter on a slab, is likely to grade a rung lower. If you have no use for the containers yourself, storing them over winter is a way of paying for floor space in order to reduce the value of your own inventory.
Questions