OPEN BAG - NM HD 6" Extra-Firm High Density Foam Mattress - King
Meet NM® HD+™ Core—mattresses built around high‑density foam for durable support, low motion transfer for quieter nights, zoned lumbar for alignment, and reinforced edges for full‑width comfort. Available in firm, medium, and plush feels across Twin, Twin XL, Full/Double, Queen, and King.
NM HD 6" Extra-Firm High-Density Foam Mattress - Enjoy Unmatched Support for Deep Sleep
Experience a transformative night’s sleep with the NM HD 6" Extra-Firm High-Density Foam Mattress, crafted for those who crave robust support and lasting comfort. Featuring an innovative high-density foam core, this mattress guarantees optimal spinal alignment and minimizes disturbances from partner movements. The soft, breathable cotton quilt enhances ventilation, providing a cool sleeping environment that suits a variety of setups—from bunk beds to compact RV mattresses.
Key Features
Exceptional Firmness: Rated 9/10 for firmness, this mattress ensures your spine stays correctly aligned while offering a solid foundation for a rejuvenating night’s sleep.
Durable High-Density Foam: Constructed from premium-grade materials typically used in commercial applications, it promises long-lasting support with minimal sagging.
Breathable Cotton Cover: The natural cotton quilted cover encourages airflow, keeping sweat and humidity at bay for a refreshing sleep surface.
Minimal Profile Height: At a sleek 6 inches, this mattress is perfect for maximizing space, especially in bunk beds or smaller living quarters.
Benefits
Canadian Craftsmanship: Proudly made in Canada, this mattress is backed by a 5-year warranty for your peace of mind, ensuring durability and quality craftsmanship.
Advanced Support System: Features a unique center and lumbar support structure, making it ideal for back and stomach sleepers seeking targeted comfort.
Swift Delivery: With free next-day delivery, you can enjoy the convenience of immediate comfort and support in your home.
Ideal For
People who require orthopedic support for uninterrupted, restful nights.
Families setting up bunk beds for kids and guests without sacrificing quality.
Anyone needing a space-saving solution that doesn’t compromise on comfort and support in their RV or studio.
Details
Product Dimensions: 76″ x 80″ (inches) – 193cm x 203cm (centimeters)
Height Profile: 6 Inches
Firmness Level: Extra Firm
Warranty: 5-Year Limited Warranty
Delivery Guarantees: Free next day delivery, 100 night sleep trial, and a price match assurance
Core Construction: Double Tempered Bonnel Coil with High Density Foam Inserts for superior durability
Comfort Layers: 2" HD+ High Density Foam X2 for enhanced comfort
Cover Material: Soft Cotton Blend for a cozy touch
Additional Durability: Equipped with Edge Guard technology to fortify longevity
Certifications: CertiPUR-US certified foams for safety and performance
Collection: Part of the HD Foam Collection
Upgrade your sleep setup with the NM HD 6" Extra-Firm Mattress, meticulously engineered for maximum comfort and robust support. Beyond just a mattress, it offers a reliable source of rejuvenating rest you can depend on every night. Elevate your sleep experience now and create your ideal sanctuary of comfort in your home!
We offer FREE DELIVERY to all major cities in Ontario and the surrounding area on orders over $199. A delivery surcharge of $45 applies to orders under $199.
Select your delivery date at checkout (if applicable) and add any special instructions in the order comments (e.g., “Ring Buzzer #1234”). If a date isn’t shown or selected at checkout, you’ll receive an email with scheduling options. Day‑of, you’ll get a text and email with a 2‑hour window and live tracking. Estimates apply to in‑stock items; rural or weather‑affected addresses may require extra time.
Barrie • Innisfil • Orillia • Midland • Collingwood • Bradford • Washago and more
1–3 days on average
Northern & Eastern Ontario
Cobourg • Peterborough • Kawartha Lakes • Minden • Haliburton • Port Perry • Bowmanville and more
1–3 days on average
Western Ontario
London • Stratford • Woodstock • Brantford • Grand Bend • Port Elgin • Tobermory and more
Need delivery outside the GTA?
We also ship to all provinces in Canada at competitive rates (territories excluded). Enter your postal code at the top of the website to see what’s available.
Ready to Sleep Better?
Shop online 24/7 or visit any National Mattress location across Ontario. Spend $199+ and relax—your new mattress will arrive quickly and free of charge locally, or ship fast across Canada.
Where does National Mattress offer free local delivery?
We offer FREE local delivery to major cities across Ontario on orders of $199+. Check the region cards above for specific cities.
Do you ship mattresses across Canada?
Yes. We ship select roll‑packed mattresses to all provinces (YT, NT, NU excluded). Transit times range from 1–2 days in ON & QC to 3–4 days in BC and NL after shipping.
Is next‑day delivery available in the GTA?
Yes. FREE next‑day local delivery is available in many GTA and surrounding areas, subject to inventory and cutoff times.
What if my Ontario local order total is under $199?
A $45 delivery surcharge applies to orders under $199.
How do I schedule or change my delivery date?
Select a date at checkout. If a chosen date isn’t available, you’ll receive an email proposing an alternative—simply reply to reschedule. In‑store purchases can be scheduled at the time of sale.
Will I get tracking updates?
Yes. Local deliveries include day‑of text/e‑mail with a 2‑hour window plus live GPS tracking. Canada‑wide shipments include a courier tracking number once picked up.
Do you deliver to Yukon, Nunavut, or the Northwest Territories?
What materials give this mattress its extra-firm feel?
This mattress uses a combination of extra-firm comfort foams and a robust support core such as high-density base foam or firm, high-gauge pocketed coils to create its extra-firm feel.
The design limits sink-in and keeps the surface very flat; see the...
What type of mattress protector should I use that wont feel hot or noisy?
Look for waterproof protectors made with soft, breathable fabrics and a quiet backing layer.
Modern protectors are often designed to feel like a regular sheet while still blocking liquids and minimizing crinkling sounds when you move at night.
Will this mattress hold its shape over time?
This extra-firm mattress is engineered with durable support and comfort materials to help maintain its shape and feel for many years under normal use.
Following the care and support guidelines on the product page will help you maximize its performance...
What are the exact dimensions of this 6 inch mattress?
If something goes wrong, do I contact you or the manufacturer for a warranty claim?
If you experience an issue that you believe is warranty-related, start by contacting the retailer where you purchased the mattress. They can guide you through the correct process, which may involve working directly with the manufacturer or submitting...
What materials and construction does this mattress use?
This mattress in a box uses a specific combination of support and comfort materials such as high-density foams, pocketed coils, or latex to deliver its feel and performance.
See the construction and materials section for a detailed breakdown of each...
Can I use this king mattress on a slatted bed frame?
Yes, most king mattresses can be used on slatted frames as long as the slats are sturdy and properly spaced.
Many manufacturers recommend slats that are no more than about 3 apart to support the mattress and prevent sagging between slats.
Does this mattress have strong edge support?
This extra-firm mattress includes edge-support features such as reinforced coils or denser foam rails to help reduce roll-off and make it comfortable to sit or sleep near the edge.
Check the product description for more details on how the edges are ...
How does this extra-firm model compare in feel to your firm and medium-firm models?
This extra-firm mattress is noticeably harder and flatter at the surface than our firm and medium-firm options.
If you want maximum support with minimal cushioning, choose this extra-firm model; if you prefer some contouring and softer pressure relief...
Is this firm mattress okay for everyday use or better for occasional sleep?
This firm mattress is designed for regular nightly use, with comfort and support features suited to sleepers who enjoy a firmer feel.
If you plan to use it every night, review the materials, firmness description, and customer reviews to confirm that...
Is this 6 inch mattress suitable for a daybed?
Yes, this 6 inch mattress can work well on many daybeds, where a lower profile looks more like a sofa during the day and is comfortable enough for lounging or occasional sleeping. Check your daybed's recommended maximum mattress height and dimensions...
Will this mattress maintain its shape and support over time?
This mattress in a box is built with materials selected to maintain their shape and support under normal use.
Review the durability information, foam densities or coil specs, and care recommendations on the product page for guidance on its expected ...
Is this mattress suitable for back-sleeping couples?
This mattress is designed to provide strong support for back sleepers along with good motion isolation, making it a solid option for couples. Its construction helps keep both partners aligned while limiting how much they feel each other's movements.
Will the edge support in this mattress remain effective as it ages?
This mattress is built with durable edge materials designed to maintain stability along the perimeter under normal use.
Review the durability specs, warranty information, and care recommendations to understand how long its edge support is expected to...
Is this king mattress comfortable for everyday use?
This king mattress is designed for regular nightly use with a balance of comfort and support suitable for its intended sleeper group (such as couples, families who co-sleep, or single adults who want extra space).
Check the firmness level, materials...
Can this mattress be used as my primary bed for the long term?
Yes, this mattress in a box is designed for regular nightly use when matched with the right base and care.
Review the durability details, warranty coverage, and recommended maintenance practices to see how it is intended to perform as a long-term primary...
Is this mattress a good choice if my partner and I have different builds?
This extra-firm mattress is designed to provide very strong support across the surface, which can help when there is a weight difference between partners.
If one partner prefers more cushioning, consider pairing this mattress with a topper on their ...
Is this 6 inch mattress supportive enough for a heavier sleeper?
This 6 inch mattress is designed primarily for lighter sleepers, children, or occasional use. Heavier sleepers may prefer a thicker mattress with more robust support and cushioning. Check the weight guidelines and product description to determine if ...
Will this 6 inch mattress feel too low in a platform bed in a small room?
A 6 inch mattress will sit lower than standard mattresses, which can be an advantage in rooms with low ceilings or small spaces. If you prefer a higher sleep surface, you can pair it with a taller bed frame or box foundation to raise the overall height...
Is this 6 inch mattress all foam or does it have springs?
This mattress uses the construction described on the product page, such as all foam or a hybrid of coils and foam. Check the materials section for details about the support core, comfort layers, and cover so you know exactly what is inside.
Is this 6 inch mattress compatible with an adjustable base?
Some 6 inch foam and hybrid mattresses are flexible enough for adjustable bases. Check the product description for notes on adjustable base compatibility and follow the manufacturer's guidelines to make sure using an adjustable base will not affect...
Will this 6 inch mattress feel different from my current thicker mattress?
Yes, a 6 inch mattress will usually feel firmer and simpler than a thicker mattress with multiple comfort layers. You may notice less sink and contouring. Check the firmness rating and user reviews on the product page to get a sense of how the feel compares...
Is this 6 inch mattress a good value for the price?
This 6 inch mattress is designed to balance cost, comfort, and support. Review the materials, warranty, and customer reviews on the product page to see how it performs in real use and whether it offers the value you expect for your budget and intended...
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