A leaking nappy often feels like a sign that you're doing something wrong. You rarely are. Leaks are almost always a small adjustment that's needed — not a failure. And the best part: there are only a handful of causes, and you can work through them in order. Here we go through why the cloth nappy leaks and how to solve it, day and night.
From Emelie: This guide is thorough — but don't let that scare you. When I was about to start with cloth nappies myself, I read for hours and was almost put off by all the information. In reality it was so much simpler. Most people who try are surprised by how rarely the nappy actually leaks — and when it does, it's nearly always a simple fix. Read what you need, skip the rest. With us, it should be easy to make a good choice.
First: how to figure out the cause
By far the most common reason a cloth nappy leaks is simply that it has become full — not that anything is wrong. And it's the easiest thing to fix. The fit, which many worry about most, is actually more forgiving than you'd think.
A simple way to figure out what's going on is to look at when it leaks:
- After longer stretches — a long play session, a nap, the night? Then it's absorbency; the nappy has simply soaked up everything it can hold. This is by far the most common.
- Right after a change? Then it's worth a quick check of the fit — usually a small adjustment is enough.
- Is the pee beading on the surface instead of being absorbed? Then the fabric may have started repelling liquid (repelling) — the least common, and easy to fix.
We'll take them below with the most common first. Usually it's quickly sorted.
1. Full nappy — the most common cause (and the simplest)
If the leak comes only after a longer stretch, the nappy has simply soaked up everything it can hold. It's the most common cause of all — and luckily the easiest to fix:
- Change a little more often. The simplest solution. A nappy that has become saturated leaks more easily.
- Add an extra insert (booster). Fold a thin insert lengthwise and place it where the pee lands first — far forward for tummy sleepers, more towards the middle or back for back sleepers. That gives you extra capacity right where it's needed.
- Turn the bamboo side towards the skin. Our inserts have a bamboo side and a stay-dry side. The bamboo side absorbs faster, which can help if the liquid runs off before it's taken up.
One common — and entirely temporary — cause: during the period when the baby drinks large amounts of milk but hasn't yet started on solid food, an extra insert may be needed for a while. Many babies take in around 200 ml per feeding, and it all has to come out in the nappy. When solid food is introduced it often decreases again — then you can remove the extra insert. Good to know, so you don't think something is wrong; it's just a phase.
One thing to know: more isn't always better. If the nappy gets too thick and tight, you can instead get compression leaks — the fabric is pressed together and the pee is squeezed out. Add a moderate amount, not the maximum, and make sure the cover still sits comfortably.
Is the leaking mostly at night? Then it's almost always this — more on nights further down.
2. The fit — but more forgiving than you think
If it leaks right after a change, it may be worth checking the fit. But rest assured: cloth nappies are forgiving, and usually a small adjustment is enough — it's rarely as fussy as you'd think. You can quickly check the following:
- The two-finger rule. You should easily be able to fit two fingers between the nappy and the child's skin — both along the waist and at the leg openings. Not tight, but not so loose that it gaps.
- The leg openings in the groin crease. Lift one leg at a time and check that the elastic sits against the skin in the crease. If the nappy sits out on the thigh instead of in the groin, it can leak as soon as the child starts to move — pull it into the crease.
- No insert fabric should stick out. If a flap of the insert sticks out along the leg or back edge, the pee is led out along the fabric — tuck all the fabric inside the cover.
- The rise snaps. Snap the nappy lower for a small child and build up gradually. It should neither pinch against the navel nor hang down towards the knees.
If you want a more detailed walkthrough with pictures, we have a whole guide on how the cloth nappy should fit.
3. Repelling — the nappy repels liquid
Sometimes an insert starts repelling liquid instead of absorbing it — the pee beads on the surface. It's almost always because the fabric has developed a film. The most common culprits:
- Fabric softener settles as a film and impairs absorbency. Never use fabric softener on cloth nappies. If it has happened anyway, don't worry — the film washes out after a few regular washes without fabric softener.
- Greasy barrier creams that end up directly in the fabric. If you apply cream, place a disposable liner on top so the cream doesn't go straight into the insert.
- New nappies that haven't been prewashed. Natural materials reach their full absorbency only after 3–5 washes — the first few times the inserts absorb a little less. Prewash new inserts a couple of times before putting them into use.
If it has already built up, usually a few washes with the right amount of detergent (dose according to the package) and an extra rinse is enough. More extensive "stripping" is only needed in exceptional cases. The full wash routine is in our wash guide for cloth nappies.
Where is it leaking? A quick map
Where the pee escapes also says something about what needs adjusting:
Up the back. Most common in the very smallest. A newborn pees often but with little force, and lies down a lot — so the pee runs upward. Change a little more often, turn the bamboo side towards the skin and fold down the front edge. More about the smallest ones is in our guide to cloth nappies for newborns.
At the legs. Almost always fit — gapping leg openings or insert fabric sticking out (see the fit section above). Less often it can be because the fabric isn't absorbing due to cream or product in the fibres (repelling) — it's clearly noticeable: the nappy doesn't feel soaked through, but leaks anyway.
Front or over the waist. Often a rise/waist adjustment, or more absorbency is needed at the front (especially for tummy sleepers).
Is it leaking at night?
The night is a chapter of its own, because the nappy stays on for many hours. Leaking at night is almost always about absorbency, not fit — the nappy simply has time to become full.
Two ways forward: add a booster (an extra insert folded lengthwise) to the nappy you already have, or switch to a dedicated night nappy. The night nappy is an extra absorbent layer made for long wear time, and it fits from 5 kg together with a roomier cover (Komfort). The full walkthrough — fit, booster tips and routine — is in our complete guide to night nappies.
Change in time — even the best nappy leaks if it stays on too long
No matter how good the fit and absorbency are, a nappy eventually leaks if it stays on too long. During the day, every 2–3 hours is a good rule of thumb, more often for the very smallest. It's not a flaw in the nappy — just a reminder to change.
When nothing helps
If you've gone through fit, absorbency and repelling and it still leaks — start over from the fit. That's almost always where the answer is, and a small adjustment of the leg openings or rise snaps solves more than you'd think. Still not leak-free? Get in touch with us, and we'll help you find the cause.
Common questions about leaks
The nappy leaks right after I've changed it — why?
Almost always the fit. Check that the leg openings sit flush with the groin, that no insert fabric sticks out, and run the two-finger rule at both the waist and legs.
It only leaks at night — what do I do?
Then it's absorbency, not fit. Add a booster (an extra insert folded lengthwise) or switch to a night nappy with a roomier cover. See the night section above.
It leaks up the back.
Most common in the smallest ones who lie down and pee with little force. Change more often, turn the bamboo side towards the skin and fold down the front edge.
A new nappy leaks — is there something wrong with it?
Rarely. Natural materials absorb fully only after 3–5 washes. Prewash new inserts a couple of times, and the absorbency will settle in.
The nappy has worked for months but suddenly leaks.
Two common reasons: the child has gotten older and pees more per session (add absorbency), or the fabric has developed a film from fabric softener/cream (repelling — see above). If you've recently changed detergent or started using cream, that's a clue.
In summary
Leaks are rarely a sign that cloth nappies "don't work" — it's almost always a small adjustment. Go through it in order: is the nappy full (most common and easiest to fix), does the fit sit well, or has the fabric started repelling liquid. And don't hesitate to get in touch if you get stuck — we're happy to help.
Want to read on? Here's the complete guide to cloth nappies and the guide on how the cloth nappy should fit.
By Emelie, founder of Time Ahead Sweden — mum of three and curious about how, as a parent, you can make thoughtful choices in everyday life.