An adjustable bed needs a mattress protector that can flex with the mattress without slipping, bunching, or leaving the surface exposed. Split configurations add another detail: you need to match the protector to the exact mattress layout, whether that means two separate Twin XL pieces or a split-top king design. These five options offer waterproof protection, with differences in padding, fabric, and fit range to help you choose.
Quick Comparison
| Product | Configuration | Standout feature | Best for |
|---|---|---|---|
| Kingnex Quilted Split King Protector | Two 39 × 80-inch pieces | Quilted microfiber padding | Shoppers who want a little extra cushioning |
| Kingnex Split Top King Protector | Split-top king, 32–34-inch upper split | Fitted design with quilted padding | Split-top king mattresses |
| SPRINGSPIRIT Split King Protector | Two 39 × 80-inch pieces | Quilted surface and long skirt | Split king mattresses with deeper sides |
| Kingnex Bamboo Split King Protector | Two 39 × 80-inch pieces | Thin bamboo-viscose jersey surface | Those who want protection without added padding |
| GRT Split King Protector | Two 39 × 80-inch pieces | Stretch fit for 5–19-inch mattress depths | Split king owners who need a broad fit range |
Our Picks: Best Waterproof Mattress Protector For Adjustable Beds reviews
1. Kingnex Quilted Split King Protector: A Soft, Padded Pair
This Kingnex set includes two fitted protectors, each sized for a 39 × 80-inch mattress. That makes it a match for many split king adjustable beds, where each side moves independently. The quilted top is made with brushed polyester fabric and microfiber fill, adding a soft layer between you and the mattress.
A TPU membrane on the underside is designed to block liquids such as sweat and spills. The all-around elastic helps hold each piece in place as the bed changes position, and the listing describes the protector as quiet. Its pockets fit mattresses up to 16 inches deep, so measure your mattress before ordering.
The added loft may suit you if you want a cushioned feel rather than a thin barrier. The trade-off is that a padded protector can change the surface feel more than an unquilted cover. For owners who prefer to keep their mattress feel as-is, the bamboo option below is a thinner alternative.
Pros:
- Includes two pieces for a split king setup
- Quilted microfiber surface adds light padding
- Waterproof TPU backing helps guard against spills
- Fitted design with pockets for mattresses up to 16 inches deep
Cons:
- Added loft may change the feel of a mattress
- Not designed for a regular king or split-top king configuration
Verdict: Choose this Kingnex set if you have a standard split king and want waterproof coverage with a soft, quilted layer.
2. Kingnex Split Top King Protector: Made for a Split at the Head
Unlike a standard split king protector, this Kingnex model is designed for a split-top king mattress. Its upper split measures 32–34 inches from the head, while the rest of the protector covers a 78 × 80-inch bed. Confirm that your mattress uses this split-top layout before buying; two separate Twin XL pieces will not provide the same fit.
The protector has a quilted, brushed polyester surface, microfiber fill, and a waterproof TPU layer. Its fitted construction is intended to stay secure as the adjustable bed moves. The pocket can accommodate mattresses up to 16 inches deep, and the care instructions call for machine washing in cold water and tumble drying on low.
Because this is a single split-top king protector rather than a pair of separate pieces, it is the most configuration-specific pick in this group. That makes it useful for the right bed, but a poor match for a regular split king. The padded top also makes it less suitable if you want a very thin protector.
Pros:
- Designed specifically for a 32–34-inch split-top king layout
- Waterproof TPU backing protects the mattress surface
- Quilted top provides a soft, padded feel
- Machine washable according to the care instructions
Cons:
- Not intended for standard split king or regular king mattresses
- Mattress depth is limited to 16 inches
Verdict: If your adjustable bed has a split-top king mattress with the specified upper split, this fitted Kingnex protector is the configuration-specific choice.
3. SPRINGSPIRIT Split King Protector: Quilted Coverage with a Long Skirt
The SPRINGSPIRIT set contains two protectors measuring 39 × 80 inches each, for a standard split king made from two Twin XL mattresses. Its quilted polyester face and fill provide a soft, padded surface, while a polyurethane waterproof layer is intended to absorb and block liquid before it reaches the mattress.
The product description says the long skirt stretches to fit mattresses up to 18 inches deep. However, its product highlight lists a pocket depth of up to 14 inches, so the supplied specifications do not agree. Check the current size details with the seller and compare them with your mattress depth before choosing this model.
SPRINGSPIRIT says the protectors are machine washable and notes that vacuum packaging may leave them looking flat or creased at first. This is a useful option if you want a quilted surface and two separate fitted pieces, but the conflicting depth information makes it less straightforward for especially tall mattresses.
Pros:
- Two separate pieces fit a standard split king layout
- Quilted polyester surface adds cushioning
- Waterproof layer is designed to protect against spills and stains
- Fitted skirt is intended to stretch around deeper mattresses
Cons:
- Listed maximum pocket depth differs between the supplied product details
- Not suitable for a regular king or split-top king bed
Verdict: Consider SPRINGSPIRIT if you want a padded split king set, but verify the pocket depth before ordering, especially if your mattresses are tall.
4. Kingnex Bamboo Split King Protector: A Thin, Unpadded Option
This Kingnex protector is made for a standard split king and comes as two fitted pieces, each measuring 39 × 80 inches. Its surface is a jersey blend listed as 70% bamboo viscose and 30% cotton. Unlike the quilted choices, it has no padding, so it is intended to protect the mattress while preserving its original feel.
A TPU coating on the reverse side provides the waterproof barrier. The product description also highlights moisture-wicking fabric and a fitted design that stays in place when the bed is adjusted. Its stretchable pockets fit mattresses up to 18 inches thick, giving it a broader stated depth range than the two Kingnex quilted options.
This design may appeal if you dislike the loft or texture of a padded mattress protector. Its thinner profile also means it does not add cushioning, so it is not the right pick if a softer, plusher surface is your goal. It is specifically sized for split king beds, not split-top king or regular king mattresses.
Pros:
- Unpadded design helps preserve the mattress feel
- Bamboo-viscose and cotton jersey surface
- Two fitted pieces suit a standard split king
- Stated to fit mattresses up to 18 inches thick
Cons:
- Does not add the cushioning of a quilted protector
- Not designed for split-top king or regular king layouts
Verdict: Pick this Kingnex model if you want a thin waterproof layer for a split king and would rather keep the mattress feel unchanged.
5. GRT Split King Protector: A Broad Stated Fit Range
The GRT set is described as one pack containing two 39 × 80-inch pieces for a split king bed. Its three-layer design includes a microfiber top, a middle layer, and a TPU backing intended to block liquids. The fitted stretch skirt is listed for mattress depths from 5 to 19 inches, a wide range that may make it worth considering if your mattress is unusually shallow or deep.
The product description states that the protector is certified to STANDARD 100 by OEKO-TEX and describes the cover as vinyl-free. It is machine washable, with instructions to use mild detergent without bleach and tumble dry on low at no more than 104°F. Follow the care label to help maintain the materials.
Fit is the main reason to consider this model, but it is still important to confirm that your bed is a standard split king. The listing specifically excludes regular king and split-top king configurations. The “one pack” wording can also be easy to misread: the product details say the pack contains two mattress protectors.
Pros:
- Two pieces are included for a standard split king
- Stated fit range covers mattress depths from 5 to 19 inches
- Three-layer construction includes a waterproof TPU backing
- Product description states STANDARD 100 by OEKO-TEX certification
Cons:
- Not suitable for regular king or split-top king beds
- Care instructions call for a low-temperature drying limit
Verdict: GRT is a practical candidate if you have a standard split king and need a protector with a broad stated mattress-depth range.
How to Choose a Waterproof Mattress Protector for an Adjustable Bed
Match the protector to your mattress layout
Start by identifying whether you have a standard split king, a split-top king, or a regular king. A standard split king usually uses two separate Twin XL mattresses, so look for a set with two 39 × 80-inch pieces. A split-top king has a different arrangement: the two sides separate near the head while the rest of the mattress remains joined. The Kingnex split-top model is designed for a 32–34-inch upper split. These configurations are not interchangeable, so check your mattress details before ordering.
Measure mattress depth, including any topper
Measure from the bottom edge of the mattress to its top surface. If you use a topper, include it in your measurement, since the protector needs to stretch over the full height. Compare that number with the product’s pocket-depth range. The options here list maximums from 16 to 19 inches, while the GRT model also gives a minimum depth. When product details disagree, as they do for the SPRINGSPIRIT protector, verify the fit information before buying.
Choose between quilted and unpadded surfaces
A quilted protector with microfiber fill can add a soft, padded layer, but it may change how your mattress feels. An unpadded protector is thinner and is designed to preserve the original surface feel. Think about whether you want a little extra cushioning or simply a barrier between the mattress and spills. A protector is not a replacement for a mattress topper if you want a larger change in firmness or support.
Check the waterproof layer and surface materials
Each product in this selection describes a TPU or polyurethane waterproof backing. The top fabric differs: options include polyester, microfiber, and a bamboo-viscose/cotton jersey blend. Consider the texture you prefer and whether you want a padded surface. Waterproof backing helps protect against liquid reaching the mattress, but follow the care instructions to maintain the protector.
Look for a secure fit that can move with the bed
Adjustable beds raise and lower at the head or foot, so a fitted design with elastic around the edges can help keep a protector in position. A correct size and pocket depth matter just as much: a loose or overstretched fit may be more likely to shift or pull as the bed moves. If you share a split king, separate protectors also let each side move independently without covering the gap with one large pad.
Review washing and drying instructions
Machine washing is listed for all five options, but the exact instructions vary. Several specify cold water and low heat, while GRT gives a maximum drying temperature. Check the product’s care label before washing, and avoid bleach where the instructions prohibit it. Following the specified routine is especially important for a protector with a waterproof backing.
Frequently Asked Questions
What type of mattress protector works best on an adjustable bed?
Look for a fitted protector that matches your mattress configuration and depth. A secure elastic skirt can help it stay in place as the bed moves. For a split king, two separate Twin XL protectors are usually the relevant format; a split-top king needs a protector designed for that layout.
Can I use a regular king protector on a split king bed?
A regular king protector is not the same as a two-piece split king set. A single cover may not fit or move properly over two independently adjustable mattresses. Choose a product that clearly lists your bed configuration.
What is the difference between split king and split-top king?
A standard split king has two separate mattresses, typically two Twin XLs. A split-top king has a split near the head of the bed but remains joined farther down. Confirm your mattress style before choosing, because a protector for one layout may not fit the other.
Will a quilted protector change how my mattress feels?
It may. Quilted options in this guide include microfiber fill that adds some loft. If you want to keep the mattress’s surface feel as close as possible to its original feel, consider a thin, unpadded style such as the Kingnex bamboo option.
How do I know whether the pockets are deep enough?
Measure the mattress from its base to its top, including any topper you plan to use. Then compare the measurement with the protector’s stated pocket depth. If the listing gives conflicting measurements, confirm the specifications before purchasing.
Are these protectors machine washable?
All five product descriptions list machine washing. Instructions vary, so check the label for water temperature, detergent guidance, and drying limits. Several specify cold washing and low-heat drying.
Do these protectors fit regular king beds?
The split king options are designed for two separate mattresses, not a single regular king mattress. The split-top Kingnex model is also intended for its specific split-top layout. Choose a protector labeled for your exact mattress size and arrangement.
Final Recommendation
For most shoppers with a standard split king adjustable bed who want added softness, the Kingnex Quilted Split King Protector is the clearest all-around choice: it includes two fitted pieces, a waterproof TPU backing, and a stated pocket depth of up to 16 inches. If you want a thinner surface, consider the Kingnex Bamboo model instead. For deeper mattresses, GRT lists the broadest fit range, while split-top king owners should choose a protector designed specifically for that configuration.
