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How to Wash a Mattress Topper (Including Memory Foam)

Memory foam and washing machines are genuinely incompatible. Everything else here follows from that.

By The CalcBold Kitchen Desk5 min readUpdated 982 words
Cooling mattress topper laid across a bed
The topper you can wash is the one with a removable cover. That is worth checking before you buy.

A mattress topper absorbs a good deal of what a sheet does not — sweat, skin cells, and the dust mites that live on them. It also happens to be one of the hardest things in a house to clean, because the most popular type cannot be washed at all.

So the first question is not how, it is what kind you own.

Table of mattress topper types and the correct cleaning method for each
Only one row here says machine wash. Check which type you own before doing anything.

Fibre and down toppers: machine washable

These are the straightforward case. Cold water, gentle cycle, mild detergent, in a machine large enough that the topper can move — a domestic drum often is not, and a launderette machine is the sensible answer for anything above a double.

  • Cold water only. Warm water can set proteins in sweat stains.
  • Half the usual detergent — bulky items rinse poorly.
  • An extra rinse cycle is worth it.
  • Dry on low heat with two or three dryer balls, which break up clumping in the filling.
  • Do not put it back on the bed until it is completely dry, including the middle.

Memory foam and latex: never

Comparison of why memory foam cannot be machine washed
Foam holds water in a way fibre does not, and the middle of a topper never dries in a normal room.
Chart of drying times for different topper types and methods
A foam topper that feels dry on the surface can still be wet in the middle for days.

Latex has the same drying problem plus a chemical one: prolonged water contact degrades it, and direct sunlight makes it brittle.

Cleaning foam properly

Five-step process for spot cleaning and deodorising a memory foam topper
Bicarbonate of soda deals with the smell. A damp cloth deals with the mark. Neither soaks the foam.

Vacuum with an upholstery attachment, both sides. This removes the skin cells that dust mites feed on and is the single most useful thing you can do.

Spot clean with a cloth that is barely damp and a drop of mild detergent. Blot, never rub — rubbing pushes the stain deeper into the foam where you cannot reach it. Blot dry hard with a towel immediately afterwards.

Deodorise by covering the surface with bicarbonate of soda and leaving it for several hours, or overnight, then vacuuming it off. It absorbs odour rather than masking it, and it is the only genuinely effective smell treatment for foam.

The strategy that avoids all of this

Put a washable protector over the topper. It costs a fraction of the topper, it goes in the machine monthly with the sheets, and it means the topper itself almost never needs cleaning at all.

Checklist of cleaning schedule and protector advice for mattress toppers
A washable protector means the topper itself almost never needs cleaning. It is the whole strategy.

When to replace it instead

Toppers do not last indefinitely. Foam softens and takes a permanent impression where you sleep; fibre fillings flatten and migrate. Both are signals that the topper has stopped doing its job, and no amount of cleaning restores support.

The practical test is whether body impressions recover after the bed has been stripped for a few hours. If they do not, it is finished.

The short version

  • Fibre and down: cold gentle machine wash, low-heat dry with dryer balls.
  • Memory foam and latex: never in a machine. Ever.
  • Foam: vacuum, blot-clean, bicarbonate of soda for smells.
  • Blot, do not rub. Rubbing drives stains deeper.
  • Use a washable protector so the topper stays clean.
  • Permanent body impressions mean replace, not clean.

If the topper is on the bed because you sleep hot, the how to sleep cooler guide covers cheaper changes worth trying first.

Common questions

Can you wash a memory foam mattress topper?
No. Machine agitation tears the open-cell foam structure, the spin cycle crushes it, and a soaked foam topper cannot be dried through in a normal home — the interior stays wet for days, which allows mould to grow inside where you cannot see it. Spot clean instead.
How do you clean a mattress topper without washing it?
Vacuum both sides with an upholstery attachment, blot any stains with a barely damp cloth and a drop of mild detergent, blot dry hard with a towel, then cover the surface with bicarbonate of soda for several hours and vacuum it off to remove odours.
How do you get a smell out of a mattress topper?
Bicarbonate of soda spread over the whole surface and left for several hours, or overnight, then vacuumed off. It absorbs odour molecules rather than masking them. Airing the topper somewhere ventilated afterwards helps, and a smell that survives both usually means moisture inside the foam.
Can you tumble dry a mattress topper?
A fibre-filled or down topper, yes — on low heat with two or three dryer balls to break up clumping in the filling. Never tumble dry memory foam or latex: the heat melts and hardens foam, and neither can be dried through anyway.
How often should you clean a mattress topper?
Vacuum monthly, air it weekly when you strip the bed, and deodorise with bicarbonate of soda quarterly. A washable protector over the topper, washed monthly with the sheets, means the topper itself rarely needs more than that.
When should you replace a mattress topper?
When body impressions no longer recover after the bed has been stripped for a few hours, when the foam has hardened or begun to crumble, or when a smell survives deodorising. Those indicate the topper has stopped providing support, and cleaning does not restore it.

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