Pallet mould and moisture content

Why 20 percent

Fresh lumber is wetter than that, and a pallet left outdoors takes up water from rain and ground damp.

Storing pallets

Keep them off the ground, on a dry base.
Cover them, but let air move through the stack.
Do not wrap a damp stack tightly; trapped water breeds mould.
Even air moving at a few feet per second helps.

Near Narragansett Bay

The bay brings damp air and fog, and a pallet stack in a back lot near the water can take up moisture over a wet spell. Seafood and cold storage docks are wetter still. A dry pallet that spends a week in a wet yard may not be dry any more.

Telling by eye and nose

Signs a pallet has gone wet
Sign	What it suggests
Dark staining along boards	Past dampness
A musty smell	Active mould or rot
Fuzzy or green patches	Surface mould
Soft or crumbling wood	Decay
White crust on nails	Moisture at the metal

A moisture meter gives a number; the nose gives a warning. Food buyers should refuse anything with a smell. See food-grade pallets and cold rooms.

Heat treatment does not make wood immune. Pallets loaded into a trailer while still hot are susceptible to mould.

Measuring moisture without a meter

A pin meter reads moisture content directly, but a few signs help without one. Wood that feels cool and slightly clammy, darkens when you press a fingernail into it, or weighs heavily for its size is probably above the safe line. Pallets that smell of cellar or wet leaves are past it. When a food or cold-room buyer is in doubt, a borrowed meter is cheaper than a rejected load.

Drying a damp pallet

Stack the pallets with spacers so air passes between them, put them under cover and move a fan across the stack. Wood dries slowly, so allow days, not hours. Mould already established can be brushed away from non-food pallets, but a pallet that smells strongly should not be used for food or in a cold room at all.