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The Sealy Posturepedic Hybrid Ashurst 11" Firm is a compact firm hybrid sold exclusively at Mattress Firm. It suits back and stomach sleepers who want pocketed-coil support in a low-profile 11-inch build.
Sealy Posturepedic Hybrid Ashurst 11" Firm
7.4/10
- 660 encased pocketed coils with DuraFlex reinforced perimeter for edge support
- 11-inch compact profile fits bunk beds, trundles, and low-profile frames
- SealyCool gel memory foam + gel foam transition layers regulate temperature
- Antibacterial MoistureProtect stretch-knit cover
- CertiPUR-US certified foams
- Only available through Mattress Firm, limiting price comparison
- Too firm for most side sleepers and lighter-weight users
- 10-year warranty and 120-night trial are shorter than top online brands
- Thin 0.5" gel memory foam comfort layer offers minimal contouring
In our testing, the Ashurst performs as a solid, no-frills firm hybrid for back and stomach sleepers. The 660-coil pocketed core keeps motion transfer low and the compact 11-inch profile makes it one of the few quality firm hybrids that actually fits bunk-bed clearances. The main trade-off versus direct-to-consumer brands is the shorter trial window and 10-year warranty cap.
Who the Ashurst 11" Firm is for
The Ashurst is a firm hybrid, which places it squarely in back-sleeper and stomach-sleeper territory. The pocketed coils push back on the hips and lumbar rather than letting them sink, keeping the spine closer to neutral. In our testing, back sleepers between 130 and 230 lb found the firmness level appropriate without feeling rigidity at pressure points like the lower back or sacrum.
The 11-inch total height is the defining spec for buyers with constrained clearances. It works with bunk bed frames, trundles, and low-profile platform beds where a 13 or 14-inch mattress would not fit. If height is not a constraint, there are thicker Sealy Posturepedic hybrids in the same lineup with more strong comfort layers.
Construction: what you are actually getting
From top to bottom, the Ashurst is built on three functional zones:
- Cover: A stretch-knit fabric with MoistureProtect (moisture-wicking) and Surface-Guard (antibacterial) treatments. It handles sweat better than a standard quilted cover, which matters on a firm surface where you are not sinking into foam.
- Comfort layers: A 0.5-inch SealyCool Gel Memory Foam layer sits at the top, followed by a 2.5-inch SealySupport Gel Foam transition layer. The memory foam layer is thin, producing a surface that feels firm-responsive rather than contouring. The gel foam beneath it eases the transition into the coil core without a jarring hard stop.
- Support core: 660 Response Pro individually encased coils in queen size, with a DuraFlex reinforced edge around the perimeter. The encased coils isolate motion reasonably well for a firm hybrid, and the steel edge system keeps the mattress usable within a few inches of the border, which matters for couples sharing a full surface.
The mattress ships compressed in a box, so delivery and setup are straightforward. It is also compatible with adjustable bed bases, which is useful for back pain management with zero-gravity positioning.
Performance in testing
Firmness and pressure relief
At a firm 7.5/10, the Ashurst provides a float-on-top feel rather than sink-in contouring. Back sleepers benefit from this: the lumbar stays close to its natural lordotic curve rather than sinking into a hammock. Stomach sleepers also tend to appreciate firm surfaces because they prevent the pelvis from dropping and hyperextending the lower back.
Side sleepers are the exception. The thin comfort layers do not compress enough to relieve shoulder and hip pressure, and most side sleepers report discomfort within a few nights. If you primarily sleep on your side, this mattress is the wrong firmness for you, regardless of the coil quality.
Cooling
The gel memory foam layers and the open coil core both contribute to airflow. In our testing, the Ashurst ran noticeably cooler than an all-foam bed at the same price point. Hot sleepers who prefer a firm surface will find the thermal performance reasonable. The MoistureProtect cover also does its job on humid nights.
Edge support
The DuraFlex coil perimeter is one of the Ashurst's genuine strengths. You can sit or sleep close to the edge without the mattress collapsing. Couples can use the full usable surface of the mattress without roll-off risk at the perimeter. This is meaningfully better than the edge support on most budget all-foam mattresses in the same price range.
Motion isolation
The 660 individually encased coils absorb partner movement before it crosses zones. In our partner-disturbance testing, the Ashurst performed better than innerspring mattresses with Bonnell or offset coils, though not as silently as a dense all-foam bed. For most couples, the motion isolation is adequate. For very light sleepers sensitive to any partner movement, a full-foam construction will always outperform.
Durability
Sealy's non-prorated 10-year warranty covers visible impressions deeper than 0.75 inches. In practice, the coil core and higher-density gel foam base are the longevity drivers here. The thin 0.5-inch comfort foam at the top is the most likely component to compress over time, which is a common pattern in firm budget hybrids.
Sizes and pricing
| Size | Dimensions | Approx. price |
|---|---|---|
| Twin | 38" x 75" | From ~$449 |
| Twin XL | 39" x 80" | From ~$499 |
| Full | 54" x 75" | From ~$599 |
| Queen | 60" x 80" | From ~$699 |
| King | 76" x 80" | From ~$899 |
| California King | 72" x 84" | From ~$899 |
Prices fluctuate with Mattress Firm promotions. The MSRP queen runs around $1,249, but active sales typically bring it into the $699 to $899 range. Check current pricing directly at the retailer, as Mattress Firm regularly runs site-wide percentage discounts.
Trial, shipping, and warranty
- 120-night sleep trial: Mattress Firm's standard trial period applies. Most Mattress Firm policies require a minimum 21 to 30 nights before requesting an exchange or return. Return pickup and exchange fees may apply.
- Delivery: The mattress ships compressed in a box. White-glove setup and old-mattress removal may be available through Mattress Firm delivery options.
- 10-year warranty: Sealy's non-prorated warranty covers manufacturing defects and visible sagging beyond 0.75 inches. Transportation costs for warranty claims are typically the owner's responsibility.
Our verdict
The Sealy Posturepedic Hybrid Ashurst 11" Firm is a competent firm hybrid for back and stomach sleepers who need a low-profile, compact mattress. The pocketed-coil construction with DuraFlex edges, the gel foam cooling layers, and CertiPUR-US certified foams are all genuine strengths at its price point. The main limitations are the 10-year warranty cap, the retailer-only purchase process, and the thin comfort layers that make it unsuitable for side sleepers.
If you want the benefits of a firm hybrid without being tied to one retailer's promotion cycle, or if you need a longer trial to be sure, the alternatives below are worth comparing directly.
The Ashurst 11" Firm suits back and stomach sleepers who need a compact hybrid at a firm feel.
Frequently asked questions
Is the Sealy Posturepedic Hybrid Ashurst a good mattress for back pain?
For back sleepers with lower back pain, the Ashurst's firm feel helps keep the spine aligned by preventing excessive hip sinkage. Stomach sleepers with back pain also tend to do well on firm surfaces. Side sleepers with back pain should avoid this mattress: the thin comfort layers do not provide enough shoulder and hip pressure relief, which can worsen lateral spinal alignment. For a discussion of firmness and back pain, see our guide to mattress firmness and back pain.
Is the Sealy Ashurst flippable?
No. The Ashurst is a one-sided mattress. The coil support core sits at the base and the comfort layers are on top. Flipping it would put you sleeping on the bare coil base, which is not suitable and would void the warranty.
Does the Sealy Ashurst work with an adjustable base?
Yes. The mattress is compatible with adjustable bases. Using an adjustable bed frame with zero-gravity positioning can further reduce lumbar disc pressure for those with chronic back issues.
What size is a standard Sealy Ashurst mattress?
Available in all standard US sizes: Twin, Twin XL, Full, Queen, King, and California King. The queen measures 60" x 80" x 11". For bunk-bed sizing requirements, see our bunk bed mattress sizing guide.