That tell-tale musty odour; the black spots or white dust… Once mould or mildew take hold on furniture or clothing, the damage can be permanent and the smell nearly impossible to shift.

While damp conditions are associated with mould and mildew, it’s not just about dampness; it’s about stagnant air and organic material.

Why is mould a problem when storing possessions?

The fungi species known as mould and mildew break down natural materials, including textiles, leather and paper. Mildew spots are also unsightly and can make books and documents unreadable.

Fungi, including mould and mildew, produce dusty spores that may trigger allergies, making mattresses and upholstered furniture unusable.

And mould can spread, too, so one mouldy item can ruin other domestic goods stored in the same space.

Here is how to keep your stored domestic goods mould free:

1. Ventilate, elevate and regulate

If you think that the space you are using for storage is prone to damp, there are some steps you can take to reduce the impact.

Airflow is your best friend when you store your stuff. A basement with stagnant air is likely to promote mould growth. So check that air bricks and vents are clear. You can also leave a breathable perimeter by keeping a hand-width gap between your boxes and the wall of your storage – this is particularly important if you’re storing in a shipping container.

Avoid laying soft furnishings like mattresses or sofas directly on a concrete floor, which can sweat if the temperature changes rapidly. Instead, elevate these items on wooden pallets.

A temperature-controlled environment is a good argument for using self-storage, rather than putting your stuff in a cellar, garage or outbuilding. This post has some tips on costing up different storage options.

2. Pack and store dry

Never store anything that is even slightly damp. This is the most common cause of mildew in storage. Here are a few suggestions for managing some of the usual suspects:

• Kitchen appliances: Defrost freezers for 48 hours and wipe them dry. Run a maintenance cycle on washing machines and ensure the internal pipes are drained. Store appliances with doors propped open.
• Outdoor gear: Tents, garden cushions, and patio umbrellas should be bone dry before you pack them. If you need to put them away during wet weather, set them up indoors to dry before they go into the unit.
• Laundry: Freshly laundered clothes often retain a tiny amount of moisture. Let them air in a warm place for a few hours before sealing them in boxes.

3. Picking the right packing materials to minimise mould

Plastic is waterproof, but it traps moisture inside, creating a kind of greenhouse where mould will thrive, so avoid plastic wrap on furniture: Never wrap leather or wood in shrink-wrap. Instead, opt for old bedsheets, moving blankets, or breathable fabric covers .

Take care with vacuum bags. While great for saving space, they can trap moisture. Ensure your clothes are 100% dry before storing them in a vacuum bag – find out more in our post on vacuum packing.

4. Preparation for long-term storage

Clean everything: Mildew feeds on organic matter, for example, dust, skin cells, and food crumbs. Vacuum your soft furnishings and wipe down wooden furniture with a mild fungicide or vinegar solution before storing will minimise these mould food sources.

Leave doors ajar: For wardrobes or fridges stored inside the unit, prop the doors open slightly (use a rolled-up sock or a piece of cardboard) to prevent the air inside from becoming musty.

Insure your stored goods

Your Store and Insure policy will cover possessions that have got mouldy because of a leak or a flood in the unit. But if your possessions were mouldy when you stored them, you cannot claim. Get a quote to find out more about costs and coverage for self-stored goods with Store and Insure.