Sierra Sleep by Ashley
Sierra Sleep Peak 2.0 12 Memory Foam Mattress
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The Sierra Sleep Peak 2.0 12 Inch Memory Foam Mattress is a straightforward pick for sleepers who already know they want a firm, supportive bed and don't need to be talked into anything softer. No hybrid coils, no marketing layers, just a purpose-built firm mattress that does one job well.
Model M206 in Ashley's Peak 2.0 collection is built entirely from foam. A high-density memory foam comfort layer sits on top, contouring just enough to cushion the shoulders and hips without letting the body sink in past that point. Underneath, a thick block of firm support foam carries the load and keeps the surface level from edge to edge, so nothing dips or sags under regular use. A soft, durable stretch knit cover wraps the full 12 inch profile, giving the top a bit of give while the foam beneath does the real work of holding you up.
Feel and Support
Because there is no coil unit in this build, the mattress behaves the way solid foam behaves: quietly. A partner rolling over, sitting up, or getting up early does not send a wave across the bed, so the movement stays on their side. The tradeoff of an all-foam, firm-leaning mattress like this one is less bounce and less of a floating sensation than a plush hybrid offers. That is by design. This bed is built for stability and even support, not for cushioning.
Who It Fits
Back and stomach sleepers tend to do best here. Firm support keeps the hips from dropping and holds the spine level through the night, which is exactly what those two positions need most. Side sleepers who prefer to rest on top of a mattress rather than sink into one will also find it comfortable, especially if they already gravitate toward a firmer feel. It is a smart, no-fuss choice for guest rooms, kids' rooms, and any bed that needs to perform reliably without a lot of upkeep.
Skip this one if you are set on a plush, sink-in feel, or if you sleep almost exclusively on your side and want deep pressure relief at the shoulder. A softer model in the Peak 2.0 line or one of our hybrid mattresses will suit that preference better.
What to Know Before You Buy
- Ships compressed in a box, plan on about 48 hours for it to fully expand once you unbox it
- Works on adjustable bases as well as a standard foundation or platform
- Backed by a 10 year non prorated warranty from Ashley
- Available in Twin, Full, Queen, King, and California King, all sharing the same foam layers and firm feel
Firm means something a little different to every sleeper. The best way to know if this one is right for you is to lie down on the Peak 2.0 12 Inch in your own sleeping position at one of our Kentucky showrooms and feel it for yourself before you decide.
What makes this mattress different
Genuinely firm, not marketing-firm
This is a real firm feel built for support, not a medium mattress labeled firm. If you already like sleeping on top of a bed rather than in one, this is that bed.
High-density memory foam comfort layer
A dense memory foam top layer cushions the shoulders and hips just enough to take the edge off a hard surface, without letting the body sink in deep.
Firm support foam base
A thick block of firm support foam underneath keeps the mattress from bottoming out, holding the spine level across the full 12 inch profile.
All-foam, quiet on a shared bed
No coil unit means no springs to transfer motion. A partner rolling over, sitting up, or getting up early is unlikely to disturb your side of the bed.
Soft stretch knit cover
A durable 4-way stretch knit cover wraps the mattress for a smooth, breathable surface that holds up to regular use.
Adjustable base compatible
Works with adjustable bases as well as a standard platform or foundation, so it fits most existing bed setups.
Ships compressed, expands fast
Arrives compressed in a box for easy delivery. Plan on about 48 hours for it to fully expand once you unbox it.
10 year non prorated warranty
Backed by Ashley's 10 year non prorated warranty, with the same foam layers and firm feel across every size from Twin to California King.
Two foam layers, one firm feel, no coils involved
The Peak 2.0 12 Inch keeps its construction simple on purpose. From the top down, the build goes a soft stretch knit cover, then a high-density memory foam comfort layer, then a thick base of firm support foam that carries most of the mattress's 12 inch height. There is no innerspring unit anywhere in the build, the firmness comes entirely from that support foam core, not from coil gauge or zoning.
That all-foam approach does two things at once. First, it keeps the surface level and stable under weight, which is what makes this mattress feel firm rather than plush. Second, it means movement does not travel across the bed the way it can on an innerspring mattress, so a restless partner is far less likely to wake you. The comfort layer is deliberately thin relative to the support core, enough memory foam to soften the immediate surface, not so much that it undoes the firm feel underneath.
See more memory foam mattresses →Built for sleepers who want firm and mean it
Back sleepers: firm support keeps the hips lifted and the spine level, which is exactly what this position needs most.
Stomach sleepers: a soft mattress lets the hips sag and the lower back arch. The firm support foam base here keeps that from happening.
Side sleepers who like a firmer bed: if you already prefer resting on top of a mattress rather than sinking into one, the shallow comfort layer over a firm core will feel right at home. Side sleepers who want a deep cradle should look elsewhere in our lineup.
Guest rooms and kids' rooms: a dependable, no-fuss firm mattress that holds up to regular use without needing much thought after the first night.
Couples sharing a bed: the all-foam build absorbs motion well, so one person's movement is unlikely to reach the other side.
Probably not for you if: you want a plush, sink-in feel, or you sleep mostly on your side and need deep pressure relief at the shoulder. A softer model in the Peak 2.0 line or one of our hybrid mattresses will fit that need better.
Specifications
| Height | 12 in |
|---|---|
| Feel | Firm |
| Firmness | Firm, built to keep the spine level rather than to cushion pressure points |
| Construction | Soft stretch knit cover over a high-density memory foam comfort layer, over a firm support foam base, 12 inches total. All-foam build, no coil unit. |
| Motion isolation | All-foam construction with no coil unit isolates movement well, so a partner shifting or getting up is unlikely to be felt on the other side of the bed. |
| Warranty | 10 year non prorated warranty from Ashley |
Frequently asked questions
How firm is the Sierra Sleep Peak 2.0 12 Inch Memory Foam Mattress?
It is a genuinely firm mattress, built to keep the spine level rather than to cushion pressure points. A thin high-density memory foam layer softens the immediate surface, but the firm support foam base underneath is doing most of the work. This is a supportive, sleep-on-top-of-it feel, not a plush hug.
What is this mattress made of?
It is built from three parts: a soft stretch knit cover, a high-density memory foam comfort layer, and a thick base of firm support foam that carries most of the 12 inch height. There is no coil unit in the build.
Is this a hybrid mattress or all-foam?
All-foam, no coils. The firm feel comes from the support foam core, not from an innerspring unit. If you are looking for the bounce and airflow of a coil-based hybrid, ask our showroom team about the hybrid options in the Peak 2.0 line.
Who sleeps best on a firm memory foam mattress like this one?
Back and stomach sleepers benefit most, since firm support keeps the hips from dropping and holds the spine level. Side sleepers who prefer resting on top of a mattress rather than sinking into one will also find it comfortable. Side sleepers who want deep shoulder cushioning should look at a softer or plusher model instead.
Can I use this mattress on an adjustable base?
Yes. The all-foam build is adjustable-base friendly, and it also sits well on a standard platform or foundation if that is what you already have.
How long does it take to expand after unboxing?
The mattress ships compressed in a box. Plan on about 48 hours after unboxing for it to fully expand to its true shape and firmness.
What warranty comes with this mattress?
It is backed by a 10 year non prorated warranty from Ashley. Keep in mind that pairing a mattress and foundation from two different brands can affect warranty coverage, so check the warranty details if you are mixing brands.
Does this mattress come with an at-home trial or comfort exchange?
No. Sierra Sleep mattresses do not include an at-home trial or comfort exchange period. Because firm feels different to every sleeper, the honest way to know if this one is right for you is to lie down on it in your own sleeping position at one of our Kentucky showrooms before you buy.
Can I see this mattress in person near me?
Yes, and with a firm mattress that is genuinely the better way to decide. Mattress Overstock is a Kentucky-owned company with showrooms in Lexington, Georgetown, Somerset, London, and Richmond. Come feel the Peak 2.0 12 Inch for yourself, and because everyone on our floor is paid the same no matter which brand you choose, the guidance you get is honest.
Buy it from people you can actually visit
- Free local delivery To your home across Central & Eastern Kentucky.
- Free setup We place and set up your new bed in the room.
- Free old-mattress haul-away The old one goes out the same day the new one comes in.
Independently owned in Kentucky since 2012. Walk in any day (no appointment) and someone who actually knows the floor will help you find the right fit.
Still deciding?
Try it in person at any Kentucky showroom
Walk into any Mattress Overstock location, lie down, and feel the difference yourself. No appointment, no pressure. Our team has over 100 years of combined mattress experience and we're here to help you find the right fit.
