TL;DR:
- Blot, never rub, and start while it is still wet. You are lifting urine out, not pressing it deeper.
- Rinse the patch with a little cool water and blot again. Skipping the rinse leaves the residue that smells later.
- Dry it hard, with a fan and an open window. Damp padding is what turns one accident into a lasting problem.
- Bleach has no place near a mattress, and baking soda is a surface deodoriser rather than a clean.
- If the smell returns once the mattress is completely dry, a professional mattress cleaning is the honest next step.
It is 2am, the bed is wet, and a child is standing beside it feeling terrible. Cleaning up is the easy part, but only in the right order: most of the lasting damage to a mattress after a bedwetting accident comes from the response, not the accident.
None of this is rare. The Royal Children's Hospital Melbourne's bedwetting factsheet calls it common between four and six, Continence Health Australia puts it at around 1 in 5 children by school age, and healthdirect still counts about 1 in 20 at age ten. Treat it as laundry and a mattress that needs a hand. Nobody is at fault, and it says nothing about behaviour.
How do you clean a mattress after a bedwetting accident?
Strip the bed, blot the urine out with dry towels, rinse the patch with a little cool water, blot again, then dry the mattress completely with air movement. That order matters more than whatever product you reach for.
- Pull everything off the bed straight away. The Sydney Children's Hospitals Network factsheet suggests keeping a mattress protector and spare bedding within reach for this moment, and washing anything urine touched promptly.
- Blot with a dry towel, pressing straight down. Stand on it if you need the weight, and move to a dry section each time it stops taking up liquid. Do not rub in circles, which spreads the patch.
- Rinse with a little cool water. Dampen a cloth, work the area lightly, blot dry again. People skip this step, and it decides whether the mattress smells next week.
- Optional: a light mist of diluted white vinegar, then blot once more. It helps with the ammonia note without anything harsh on the fabric.
- Dry it properly. Fan on the patch, window open, mattress stood on its side so air reaches both faces.
Cool water, not hot: heat sets protein-based stains.
Why does a wet mattress start to smell?
Because urine leaves residue behind when the water evaporates, and that residue is what bacteria feed on. Urine is mostly water, with urea, uric acid and salts making up the rest. The water leaves within a day; everything else stays where it landed.
Urea is the part that matters. As it breaks down it gives off ammonia, the sharp note you get walking into the room days later, and it returns on any humid day because the residue is still there to react.
It is the same reason a damp smell in carpet returns after it has apparently dried. Moisture is the trigger, not the cause.
What you should not put on a wet mattress
Bleach is first on the list. It damages fabric, it can lighten colour permanently, and mixing it with the ammonia in urine is a bad idea: Poison Control notes that bleach combined with ammonia produces chloramine gas. No part of this job needs it.
Second, go carefully with supermarket spot removers. I have seen enough carpet permanently lightened by products that behave like a mild bleach to be wary of one on a mattress. If you do not know what is in it, test somewhere hidden.
Third, and this does the most quiet harm: do not flood it. Whatever goes into a mattress has to come back out through the same surface. That goes double for pure memory foam and latex, which hold water in the core and should not be wet extracted at all.
Does baking soda actually clean a mattress?
No. It deodorises the surface, which is a useful last step and a poor substitute for the first three. This is the most common misunderstanding I meet on mattress jobs: people believe a layer left overnight has disinfected the bed, when it has absorbed some moisture and masked some smell in the top few millimetres of fabric.
I take the same view of scented deodorising powders. On carpet they settle deep into the fibre and hold dirt there rather than fixing anything, and a mattress gives them even less chance of coming back out. Use one after blotting and rinsing if you like, but not as the whole plan.
How do you dry a mattress properly?
Move air across it until it is fully dry, and treat that as the most important part of the job, not the tidy-up at the end. A fan on the patch, a window open, and the mattress angled so air reaches underneath beat patience.
The reason to hurry is mould. The US EPA's guidance is that in most cases mould will not grow if wet materials are dried within 24 to 48 hours, and it warns that porous materials left damp beyond 48 hours may end up thrown out rather than cleaned. A mattress is about as porous as household items get.
Victoria's Better Health Channel makes the same point from the health side: mould only grows where there is sufficient moisture, and it can trigger congestion, coughing and wheezing, and worsen asthma.
Dust mites like the same conditions. They prefer warm and humid environments and feed on shed skin, so a bed is already their best address without you adding moisture. Better Health Channel also suggests washing sheets and pillowcases weekly in water hotter than 60 °C, worth knowing for the bedding that came off tonight.
The over-wetting mistake that turns a small accident into a big one
One job I still think about was a carpet, not a mattress, but the lesson transfers exactly. A homeowner had run a hired machine over their living room with too much water and the vacuum switched off, and it soaked the backing and the wooden subfloor. By the time I arrived it had gone sour. About an hour and a half of extraction and treatment brought it back.
A mattress is the same trap with less margin, because there is no backing and nowhere for water to go. The damage is rarely the urine. It is the litre of solution sprayed on to fix the urine.
Our own upholstery cleaning runs on the opposite principle: as little moisture as the job allows, and repeated dry passes to pull back what did go in.
When is it worth cleaning a mattress professionally after bedwetting?
When the smell returns after the mattress is completely dry, when accidents have gone on for months, or when the mark is old enough that you have stopped noticing it. All three mean the urine went past the surface.
A professional mattress clean is a pre-treatment, extraction with an upholstery hand tool, general sanitising and deodorising, done on one side, with drying guidance afterwards. A queen takes about an hour and is usually dry within a few hours, and we give you a realistic time on the day rather than a number off a website. Pricing goes by mattress size, one side at a time, with a minimum per visit.
What we will not do is promise a stain is coming out before we have seen it. Old sweat rings and deep urine discolouration have already changed the fabric colour, so cleaning takes out the residue and the odour rather than the shadow. The honest promise there is a noticeable improvement, not a new mattress. Everything carries a 7-day satisfaction guarantee.
If pets are part of the picture, that is a different treatment quoted separately, because urine odour soaked into padding needs an enzyme treatment rather than a wash. The same logic decides whether a mattress clean is worth it.
Can you stop the next accident reaching the mattress?
Mostly, yes, with a waterproof protector, and it is the highest-value thing on this page. Protectors are what stop bedwetting damaging mattresses in the first place. The Royal Children's Hospital lists waterproof mattress and pillow protectors and bedwetting sheets as good options. Once one is on, an accident is a load of washing, not a mattress problem.
Two additions that cost nothing. Make the bed in two layers, protector, sheet, protector, sheet, so at 2am you strip one layer and everyone goes back to sleep. Keep the spare set beside the bed.
If the bedwetting itself is wearing everyone down, that is a conversation for a GP or a continence nurse, not a cleaner. Continence Health Australia suggests raising it if it continues past six or seven, or sooner if your child is upset by it.
Frequently asked questions
Does baking soda remove urine smell from a mattress?
It reduces the smell on the surface, and that is all it does. A dry powder cannot reach urine that has soaked into the padding, because it does not travel down and does not lift anything back out. Use it after blotting and rinsing, then vacuum every trace off.
Can you use vinegar to clean a mattress?
Diluted white vinegar is a reasonable second step on a fresh accident, once you have blotted out as much urine as you can. It is mildly acidic, which helps against the ammonia smell, and far safer on fabric than bleach. Use as little liquid as possible: a soaked mattress is worse off than one left alone.
How long does a mattress take to dry after a bedwetting accident?
It depends on how much liquid went in, how thick the mattress is and how well the room moves air, so nobody can give an honest number sight unseen. The target matters more than the clock: fully dry, not nearly dry, and quickly.
Is it safe to sleep on a mattress that still smells of urine?
A lingering smell means residue is still in the mattress, and usually that the padding has not fully dried. That is worth fixing rather than covering up, because damp bedding material is where mould and dust mites do well.
Can a professional clean remove old urine stains from a mattress?
Often it improves them a lot, and sometimes the mark stays. Once urine has had time to change the fabric colour, cleaning takes out the residue and the smell rather than the shadow. We will tell you on the day which of the two you are looking at. Fresh accidents usually come out.
