Humidity and mould in storage

Mould is the thing that actually ruins stored belongings in Ho Chi Minh City. Not theft, not damp floors, not rats: a season of warm air at eighty percent humidity on a leather bag that went in slightly damp. This is what grows, what it grows on, and the two things that stop it.

Updated September 2026

The Tủ Mây collection crew outside a house in Ho Chi Minh City

The short answer

Mould grows when air stays above roughly two thirds relative humidity for days. Ho Chi Minh City is above that for most of the rainy season, May to November, and often in the dry season too.
It grows on anything organic with a little moisture: leather, paper, cotton, wood, the dust on a mattress. It does not care whether the item is expensive.
Two defences. Preparation: everything goes in clean, fully dry and not sealed in plastic. Climate: the air-conditioned sections run at 23 to 25°C, and cooling the air dries it.
Leather, books, photographs, wood veneer, mattresses and electronics belong in the air-conditioned section. Plastic, metal, glass, tools and sealed cartons of hard goods are fine in standard.

Why Saigon is a mould city

Mould spores are everywhere and always; they need three things to grow into a colony: an organic surface, warmth, and moisture in the air above roughly 65 to 70 percent relative humidity for a sustained period. Ho Chi Minh City provides all three for most of the year. Daytime temperatures of 28 to 35°C, and relative humidity that sits between 75 and 85 percent in the rainy season and drops only briefly in the driest months, mean a wardrobe door left shut in an unoccupied flat can grow a grey bloom on every leather item inside within a few weeks. Storage is the same flat with the door shut for longer.

What grows on what

Risk by material
Item	What happens	Section
Leather bags, shoes, belts, jackets	White or green bloom in weeks; stiffening and cracking over months	Air-conditioned, wrapped in cotton or paper, never plastic
Books, papers, photographs, artwork	Foxing, wavy pages, pages sticking, smell that never leaves	Air-conditioned, boxed upright, off the floor
Cotton and linen clothing, bedding	Musty smell first, then spots that do not wash out	Air-conditioned for more than a season; standard is acceptable for a few dry-season months if fully dry going in
Wool, silk, down	Mould and moth together; down clumps	Air-conditioned
Mattresses and upholstered furniture	Mould in the foam and fabric, feeding on the dust; often invisible until the smell	Air-conditioned, in a breathable cover, on edge or flat on a rack
Solid wood furniture	Surface mould on unfinished areas and the back panels; joints swell	Air-conditioned for antiques and veneer; standard tolerable for solid, finished pieces
Chipboard and MDF flat-pack	Swells at the edges and never shrinks back	Air-conditioned, or reconsider storing it at all
Electronics, cameras, instruments	Fungus on lenses, corrosion on contacts, warped soundboards	Air-conditioned, with silica gel in the case
Plastic, metal, glass, ceramics, tools	Little; metal may spot in standard over a long time	Standard
Appliances	Mould in the drum, the seal and the ice tray if stored wet	Standard, if drained, defrosted and dried with doors ajar

Preparation matters more than the section

An air-conditioned room will not save a damp item; it slows the damage. Almost every mould claim in storage traces back to the day of packing. The rules are short and none of them are optional.

Wash and dry everything textile, then let it air a further day indoors with the fan on. Line-dried clothes in the rainy season are rarely fully dry.
Clean leather, let it dry, condition it lightly and stuff bags and shoes with paper. Wrap in cotton or acid-free paper. Never in plastic: plastic seals the moisture in with the spores.
Wipe wood with a dry cloth; do not polish or oil the week before storage.
Defrost the fridge 48 hours ahead, dry the inside, tape the door ajar. Drain the washing machine, run a hot empty cycle, leave the door and the drawer open for a day. Bag the hoses.
Electronics: remove batteries, put a sachet of silica gel in each case, and store in the original box if you have it.
Use cardboard boxes, not sealed plastic tubs, for anything organic. Cardboard breathes; a sealed tub with one damp jumper is a greenhouse.
Nothing goes on the floor. Our racking takes care of that; if you self-store, buy pallets.

What the air-conditioned section does

Cooling air lowers its capacity to hold water, which is why a running air conditioner drips: the moisture condenses out. The air-conditioned sections of our facilities run at 23 to 25°C around the clock, which takes the air out of the range where mould grows quickly and keeps it there. It is not a dry room, and it is not cold storage; it is the climate of an air-conditioned office, all day, every day, which is what leather, paper and fabric want. Every one of our five facilities has both standard and air-conditioned sections, so a plan can be split: the bicycle and the tools in standard, the wardrobe and the books in air-conditioned.

What standard storage is good for

The standard sections are covered, racked and pest-controlled but at the ambient temperature and humidity of the city. They cost less: 1,250,000 VND against 1,550,000 VND a month for a Small valet plan. That is the right choice for hard goods, for appliances that have been dried properly, and for cartons of things that do not mind the air: crockery, tools, plastic, sports equipment, boxed metal. It is the wrong choice for a mattress, a leather sofa or a box of books for longer than a few weeks.

If mould has already started

Fabric: wash hot where the label allows, dry in full sun, and then air-conditioned storage. Spots on cotton may be permanent; the smell usually goes.
Leather: brush dry in sunlight, wipe with a cloth barely damp with diluted white vinegar, dry fully, condition. Deep mould in the lining is usually a loss.
Books: stand them open in a dry, sunny room with a fan; brush the spores off outdoors. Do not store them with clean books until they are dry and no longer smell.
Wood: wipe with diluted vinegar, dry, and sand lightly if the finish is gone. Chipboard that has swollen does not recover.
Mattress: sun both sides for a day, vacuum, and store in a breathable cover. If the smell persists after two days of sun, the foam is colonised.

Pests are the other half

Humidity brings silverfish, booklice and cockroaches as reliably as it brings mould; all three eat paper, glue and starch. Our facilities have professional pest control on a schedule. Your part is the same as for mould: nothing goes in with food residue on it, boxes are taped shut, and nothing organic sits on the floor.

Tủ Mây price list · standard / air-conditioned

Valet · Small · 12 boxes1,250,000 VND / 1,550,000 VND

Valet · Medium · 24 boxes2,450,000 VND / 3,050,000 VND

Valet · Large · 48 boxes4,900,000 VND / 6,150,000 VND

Self storage · Small1,550,000 VND / 1,950,000 VND

Self storage · Medium3,050,000 VND / 3,800,000 VND

Self storage · Large6,150,000 VND / 7,700,000 VND

Collection only, paid oncefrom 3,300,000 VND

Collection and return, paid oncefrom 5,100,000 VND

A delivery in between, per trip500,000 VND, 5 boxes included

Store 3 / 6 / 12 months5% / 10% / 15% off

Frequently asked

Is standard storage safe in the rainy season?

For hard goods, yes. For leather, paper, fabric and mattresses, use the air-conditioned section; a rainy season in ambient air is long enough for mould to establish on those.

Do you inspect items for mould while they are stored?

Every item is photographed when it comes in and when it moves. Items are not opened during storage. Preparation on packing day is what protects them.

Can I put silica gel in my boxes?

Yes, and it helps for electronics and leather in a closed case. It does not replace drying the item first.

Are plastic storage tubs better than cardboard?

For hard goods, either. For anything organic, cardboard: it lets moisture out, whereas a sealed tub traps it with the item.

What is the difference between the sections in price?

For valet storage: 1,250,000 against 1,550,000 VND a month for Small, 2,450,000 against 3,050,000 for Medium, 4,900,000 against 6,150,000 for Large. Plans can be split across both.

Store it, get it back when you need it

We come to you, pack, photograph every item and keep it in climate-controlled storage. One message brings any of it back.

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