Long-term storage
Researched and written by Ashley Davis · Reviewed by Emily Johnson · Last reviewed August 2026
Long-term storage fails slowly, so the preparation is different from a stay of a few weeks. Everything goes in clean and dry, off the concrete, covered in breathable material rather than sealed plastic, with batteries, liquids and anything edible removed. Put a date in the calendar to open the unit and inspect it, because the damage that matters in a long stay is the kind that is cheap to fix in month two and unrecoverable in month fourteen.
When does storage count as long term?
Past a full season, and certainly past a year. The threshold is not a date on a contract but a weather cycle: once the contents have sat through a summer and a winter they have been through the full range of temperature and humidity the building can produce, and anything that was going to warp, mould or corrode has started.
What preparation does a long stay need?
Four things beyond a normal load. Clean and fully dry every item, since residue and damp both have time to work. Empty anything that holds liquid, including appliance lines and hoses. Remove every battery, because a leaking cell ruins whatever it sits in. And raise the entire load off the slab on pallets or boards so ground moisture cannot wick up into it.
How do you keep pests out over months?
Remove the food source rather than relying on a deterrent. No food of any kind, including sealed dry goods and pet food, which is the commonest cause of an infestation in a clean facility. Textiles, bedding and clothing go into rigid sealed bins rather than cardboard, since cardboard is both a food and a nesting material. The storing clothes page covers the textile side in more detail.
What should not go into long-term storage at all?
Anything that is irreplaceable or that you may need at short notice. Passports, deeds, wills, medical records and tax papers belong with you rather than behind a roller door across town. Jewellery and cash are excluded from most facility contracts and from most storage insurance policies outright, which means they are not merely unprotected but explicitly not covered.
How often should you check a long-term unit?
Every three months is a reasonable rhythm, and after any severe weather. You are looking for three things: water marks on the floor and the lower boxes, any smell of damp, and droppings or chewed cardboard. All three are cheap to answer early. Confirm at the same time that the facility still holds current contact details, since a lapsed payment on an unread email is how units are auctioned.