Why Does My Reusable Nappy Leak? Fixing Fit Issues
By LittleLamb | Published: 2026-10-17
Category: Tips & Care
Leaks from reusable nappies usually mean a fit problem. Learn to diagnose the cause and fix it with simple adjustments, from leg gussets to absorbency.
Quick answer
A leaking reusable nappy almost always points to a fit or absorbency issue, not a product failure. Check the leg gussets for gaps, ensure the nappy is positioned low in the front, and confirm you're using the right absorbency for your baby's output. Most leaks stop with one or two simple adjustments.
Common leak patterns and what they mean
Leaks at the legs usually mean the elastics aren't sitting in the natural leg crease, or the nappy is too loose. Leaks up the back often mean the nappy isn't pulled high enough at the back, or the waist is gaping. Leaks through the front of the nappy point to insufficient absorbency or a nappy that's too small. If the leak is all over, the nappy may be saturated beyond its capacity, or the waterproof layer might be compromised.
Step-by-step fit check
Start by fastening the nappy snugly but not tight — you should be able to slide one finger between the waist and your baby's belly. Check that the inner leg gussets (if present) are tucked outwards, creating a barrier. Pull the back of the nappy up so it sits at the waist, not low on the hips. For boys, point the penis downward to direct urine into the absorbent core. If you're using a one-size nappy, double-check that the rise snaps are set correctly for your baby's weight and size.
When absorbency is the real issue
A well-fitted nappy can still leak if it's not absorbent enough for your baby's output. Heavy wetters may need a booster insert or a more absorbent material like hemp or bamboo. If you're using microfiber inserts, they can compress under pressure and leak. Try adding a natural-fiber booster underneath the microfiber. Also, remember that cloth nappies need proper washing to stay absorbent — detergent buildup or mineral deposits can cause repelling, which looks like a leak.
When to consider a different product
If you've tried all the fit and absorbency adjustments and still get leaks, the nappy may simply not suit your baby's shape. Some brands run narrower or wider in the crotch, and some babies have very slim thighs or chunky thighs. In that case, trying a different style or brand can solve the issue. For example, the LittleLamb Lamby Safari Leggings are designed with extra room to fit over reusable nappies, which can help keep everything in place and reduce leaks caused by clothing that presses the nappy out of position.
Leak diagnosis at a glance
- Symptom: Leg leaks: Wetness appears on the inner thigh or along the leg elastic line. Check that the leg gussets are tucked out and the nappy sits in the leg crease. Tighten the waist or try a smaller rise setting.
- Symptom: Back leaks: Wetness appears on the back of the nappy or clothing above the waist. Pull the nappy higher at the back. Ensure the waistband is snug. If your baby is a back sleeper, add a booster at the back.
- Symptom: Front leaks: Wetness appears on the front of the nappy or clothing below the belly. Increase absorbency with a booster or switch to a more absorbent insert. For boys, ensure the penis is pointed down.
- Symptom: Leaks everywhere: The nappy feels heavy and wet all over, and urine seeps out from multiple points. The nappy is saturated. Change more frequently or use a more absorbent setup. If the waterproof layer is damaged, replace the nappy.
Products that can help
- Lamby Safari Leggings - Designed for Reusable Nappies: LittleLamb's Lamby Safari leggings are made in sustainable organic cotton, with a stretchy waistband to fit over reusable nappies. Tight or non-stretchy outer clothing can push a nappy out of alignment, causing leaks. These leggings accommodate the bulk of a cloth nappy without compressing it, helping maintain the fit you've carefully adjusted.
- Nappy Pail for Reusable Nappies: We’ve completely rethought the nappy bucket for reusable nappies! Inspired by the dry bags used for boating, our new Nappy Pail for Reusable Nappies is here to make your life easier. Super waterproof and designed for convenience, it’s got a quick-zip for adding nappies (and for keeping smells contained) and a big top opening so you can empty everything into the washing machine without touching a thing. Once you've fixed the leak, storing used nappies properly keeps smells contained and makes wash day simpler. This pail's design lets you dump the whole load directly into the machine, saving time and effort.
