If you’re choosing mattress protection for a child who wets the bed, you’ll encounter two main formats: the fitted mattress protector and the encasement mattress protector. Both serve their purpose but differ in how they do so, and for heavy or frequent bedwetting, the distinction is important.
This guide explains how each type works, their practical differences, and which might suit your situation.
What Is a Fitted Mattress Protector?
A fitted protector covers the top and sides of the mattress—similar to a fitted sheet. It has elasticated corners that tuck underneath, leaving the mattress base and underside exposed.
Most waterproof fitted protectors use a polyurethane (PU) membrane laminated to a soft fabric surface. The membrane prevents liquids from passing through to the mattress, while the top layer feels relatively normal against a sheet.
Advantages of fitted protectors
- Easy to put on and remove—useful when changing bedding at 3am
- Machine washable and usually tumble-dryer safe
- Available in a range of sizes, including cot, single, double, and king
- Lower cost—typically £10–£30 depending on brand and quality
- Breathable options are available, which can improve overnight comfort
Limitations of fitted protectors
- The sides and base of the mattress remain unprotected
- Heavy or pooling leaks can sometimes seep around the edges
- The elasticated underside can allow moisture to wick down if saturation is significant
- Does not protect against dust mites, allergens, or bed bugs entering the mattress from below
For most children with bedwetting, a good-quality fitted protector is sufficient—especially when paired with an absorbent product. The exposed base is rarely an issue unless leaks are very heavy or the mattress is old and damaged.
What Is an Encasement Mattress Protector?
An encasement completely surrounds the mattress on all six sides. It zips shut, sealing the mattress inside. No part of the mattress is exposed to liquids or the environment.
Originally developed as anti-allergy products to block dust mite allergens, encasements are also widely used for moisture protection, especially in healthcare settings.
Advantages of encasements
- Complete protection—liquid cannot reach any part of the mattress
- Prevents long-term odour build-up inside the mattress foam or springs
- Protects investment in expensive mattresses (memory foam, orthopaedic, etc.)
- Dual-purpose: also blocks allergens, dust mites, and bed bugs
- Particularly useful where leaks are very heavy or frequent
Limitations of encasements
- More difficult to remove and refit—especially during the night
- Some may feel noticeably crinkly or warm, depending on the material
- Generally more expensive—typically £20–£60 or more for quality options
- The zip can wear over time and become a weak point if not well made
- You still need a separate fitted layer on top for comfort during sleep
Fitted vs Encasement: The Core Practical Difference
The key difference lies in how often leaks reach the mattress surface and what you are protecting against.
If your child wears an absorbent product overnight (pull-ups, taped briefs, boosted pads), the mattress protector acts as a secondary defence. A good fitted protector handles this well in most cases. The mattress base is rarely at risk.
If your child sleeps without a product, experiences heavy or frequent leaks, or if previous leaks have damaged the mattress, an encasement offers better long-term protection—especially for foam mattresses, which are difficult to dry once saturated.
Foam and memory foam mattresses cannot be dried from the inside out. A significant leak reaching the core can cause permanent odour. If the mattress costs over £200, an encasement can be cost-effective after a few incidents.
Which Should You Choose?
Choose a fitted protector if:
- Your child uses an absorbent product most or all nights
- Leaks are infrequent or moderate
- You need quick and easy bedding changes
- The mattress is inexpensive or older, and replacement isn’t a concern
- Budget considerations—prioritise a good fitted protector over a cheap encasement
Choose an encasement if:
- Leaks are very heavy and frequent
- Your child sleeps without a product
- The mattress is expensive (memory foam, orthopaedic, or specialist)
- You are managing allergies or sensitivities
- Previous leaks have damaged the mattress, and you want to prevent future damage
Using both together
Many families use an encasement as a permanent base layer—zipped and left in place—and a washable fitted protector on top for daily changes. The encasement stays put; the fitted layer is removed and washed. This combination is practical for frequent or heavy wetting and is common in healthcare settings.
If the fitted layer ever fails during a significant leak, the encasement catches the liquid, keeping the mattress dry.
Material and Comfort Considerations
Waterproof membranes vary. Cheaper options use thick PVC, which can feel stiff and crinkly, potentially disruptive for light sleepers or children with sensory sensitivities. Better options use thinner, softer PU laminates that are quieter and more breathable.
For children with autism or sensory processing differences, this is especially important. Noisy or uncomfortable protectors can hinder sleep. Look for products labelled “quiet” or “breathable”—or test a fitted protector before investing in an encasement, as encasements are often less forgiving on texture and sound.
If managing sensory sensitivities is a priority, consider reading our guide on managing bedwetting stress as a family.
Care and Longevity
Most waterproof fitted protectors can be washed at 60°C, which is important for hygiene with frequent use. Check the label—some cheaper protectors may delaminate after repeated washing or high-heat drying. A protector lasting 6 months of nightly use may be less cost-effective than a more durable one lasting 3 years.
Encasements are generally washed less frequently but still require cleaning. Ensure the zip is reinforced and seams are heat-welded rather than sewn, as stitched seams are not fully waterproof and can allow moisture through under pressure.
What About Bed Pads and Mats?
Both protector types work well with a bed pad or absorbent mat placed over the fitted sheet. Pads absorb immediate leaks, reducing the amount reaching the protector layer, and can often be changed quickly during the night without stripping the bed.
This layered approach (encasement + fitted protector + absorbent pad + sheet) is most effective for children who wet heavily and reduces laundry over time. It is common in paediatric care settings for this reason.
Learn more about how product design influences leaks and why mattress protection is necessary in our article on why overnight pull-ups leak.
Cost Summary
- Budget fitted protector: £8–£15—adequate for light or infrequent wetting; check wash durability
- Mid-range fitted protector: £15–£30—better membrane, quieter, more breathable; suitable for ongoing bedwetting
- Quality encasement: £25–£60—full mattress protection; recommended for expensive mattresses or heavy nightly wetting
- Both combined: £40–£80—the most comprehensive option for severe or persistent bedwetting
Fitted vs Encasement Mattress Protectors: The Bottom Line
For most families, a good-quality fitted mattress protector is a practical starting point—easy to change and sufficient when paired with an absorbent product. If bedwetting is heavy or the mattress is valuable, an encasement offers better long-term protection and may be worth the extra cost.
The most effective solution for heavy nightly wetting is to use both: an encasement underneath and a washable fitted layer on top, which can be changed as needed.
If you’re looking to reduce the frequency of full bed changes, our guide on how other parents manage night changes offers practical layering strategies. To understand whether wetting frequency can be reduced, consider consulting a healthcare professional.