If you have a deep mattress — memory foam, hybrid, or anything over 25cm — finding a waterproof protector that actually stays put can be challenging. The Silentnight Waterproof Deep Mattress Protector is widely available in the UK, and a key question parents ask is: how deep a mattress does it fit? The answer is up to 38cm, which covers most UK mattresses. Here is everything you need to know before buying.
What Depth Mattress Does the Silentnight Waterproof Deep Mattress Protector Fit?
The Silentnight Waterproof Deep Mattress Protector is designed to fit mattresses up to 38cm (approximately 15 inches) deep. This is achieved through a generously elasticated skirt — a fitted sheet-style design rather than a flat pad — that wraps under the mattress and holds in place through the night.
For context:
- Budget single mattresses: typically 15–20cm deep
- Mid-range mattresses: typically 20–28cm deep
- Premium, hybrid, or memory foam mattresses: typically 28–35cm deep
- Ultra-deep or luxury mattresses: can exceed 35cm, occasionally reaching 40cm+
In practice, a 38cm limit comfortably covers most UK household mattresses, including memory foam and hybrid models. If your mattress exceeds 38cm — which is rare — this protector may not fit securely, so check your mattress depth before purchasing.
Children’s mattresses, including standard single and bunk bed sizes, are usually well within this limit. Bunk bed mattresses tend to be shallower (10–18cm) for safety, so the deep-fit skirt will have plenty of room to tuck under.
Construction and Materials
Top Surface
The top layer is terry cotton, offering a soft, towelling feel rather than a plastic surface. This is beneficial for children sensitive to textures or who sleep better without a plastic-like feel.
Terry towelling also tends to be quieter than plastic-backed protectors, with less crinkling noise, though some sound may occur when a child moves significantly. Overall, it is among the quieter options in its price range.
Waterproof Layer
Below the terry surface is a waterproof barrier designed to prevent liquids from reaching the mattress. This is essential for managing bedwetting, as it protects the mattress from damage and odour.
It’s important to understand that a mattress protector does not contain urine or keep the child dry; it is a protective layer for the mattress itself. It is not a substitute for absorbent nightwear or pull-ups.
Washing
The Silentnight Deep Mattress Protector is machine washable at 60°C, which is effective for hygiene and bacteria removal. Many cheaper protectors only wash at 40°C, making the 60°C wash an advantage for frequent laundry.
Sizes Available
The protector is available in standard UK sizes:
- Single
- Double
- King
- Super King
It is suitable for most children’s beds and adult mattresses in these sizes.
Where to Buy and Approximate Cost
The Silentnight Waterproof Deep Mattress Protector can be purchased from Amazon, John Lewis, Argos, and directly from Silentnight. Prices are roughly:
- Single: £18–£25
- Double: £22–£30
- King: £28–£38
Prices vary with promotions and retailers. Buying multiple protectors can be practical for managing frequent wet nights.
Is This the Right Mattress Protector for Bedwetting?
A fitted waterproof mattress protector is a practical foundation for bedwetting management. It protects the mattress from damage and odour if leaks occur, but it does not replace absorbent nightwear or bed pads. For heavy or frequent wetting, a layered approach—using a protector plus absorbent products—is recommended.
Sensory Considerations
For children with sensory sensitivities, the terry surface is softer and less noisy than many alternatives. It is not completely silent, but it is quieter than plastic-backed protectors, which can be important for some children.
What It Does Not Do
This protector does not reduce how often your child wets, improve containment, or address underlying bedwetting causes. It simply protects the mattress, which is a valuable part of managing bedwetting.
Verdict: Does the Depth Work?
The Silentnight Waterproof Deep Mattress Protector fits mattresses up to 38cm deep, covering most UK mattresses, including thick memory foam and hybrid models. For children’s beds, bunk beds, and guest beds, it should fit well. Measure your mattress if unsure. Most UK single mattresses are well below 30cm deep, so fit is usually not an issue.
For more on how mattress protection fits into bedwetting management, see our overview of common issues with overnight leaks.