NM® HD+™ Core Mattress Collection — High‑Density Foam, Zoned Lumbar & Edge Support Compatible with Adjustable Bed Adjustable Bed Compatible Mattresses Grey Mattresses Silver-Tone Mattresses Mattress Selector

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.
Not every mattress can bend with an adjustable base — but these can. Every mattress here is built to flex with the head and foot articulation of an adjustable base without damaging the comfort layers, so you can read, relax in Zero-Gravity or elevate your legs with confidence. In fact, over 90% of our mattresses are adjustable-compatible, spanning memory foam, hybrid and pocket-coil constructions from every brand — NM, Sealy, Serta, Beautyrest, Tempur-Pedic, Stearns & Foster and more — at every budget from about $109 to premium. Foam and hybrid models flex most easily, while rigid, thick tight-top innersprings generally don't. Pair any of these with one of our adjustable bases, and every mattress comes with a 365-night sleep trial and free delivery across Canada. • What this means: mattresses built to flex with an adjustable base's head & foot articulation • Over 90% of our mattresses are adjustable-compatible — every brand, every budget ($109+) • Best constructions for adjustable bases: memory foam, hybrid and pocket-coil • What usually won't work: rigid, thick tight-top innersprings that don't bend • Pairs with our adjustable bases (including split-king for independent sides) • Every order: 365-night sleep trial, price-match guarantee & free Canada-wide delivery
These mattresses feature a grey or neutral-tone cover — and since that cover sits under your sheets, colour won't change how you sleep. To find the right bed, shop by size (twin to king), comfort (plush, medium, firm), or type (memory foam, hybrid, pocket coil). Every mattress includes a 365-night sleep trial and free delivery across Canada.
These mattresses feature a silver or grey-tone cover — and since that cover sits under your sheets, colour won't change how you sleep. To find the right bed, shop by size (twin to king), comfort (plush, medium, firm), or type (memory foam, hybrid, pocket coil). Every mattress includes a 365-night sleep trial and free delivery across Canada.
NM® HD+™ Core Mattress Collection — High‑Density Foam, Zoned Lumbar & Edge Support Compatible with Adjustable Bed Adjustable Bed Compatible Mattresses Grey Mattresses Silver-Tone Mattresses Mattress Selector

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Clear all NM® HD+™ Core Compatible with Adjustable Bed Compatible with Adjustable Bed Base Grey Silver

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NM® HD+™ Core Compatible with Adjustable Bed Compatible with Adjustable Bed Base Grey Silver Clear all
  • NM® HD+™ Core 6" Extra-Firm High Density Foam Mattress
    BEST IN CLASS BEST SELLING TOP RATED
    National Mattress HD 6-inch extra-firm foam mattress, grey damask tight-top, charcoal sides, Canada-flag badge NM Logo
    EX-FIRM
    • High Density Foam Core
    • High Density Foam Comfort Layer
    • Cotton Support Quilt
    • 5 Year Warranty
    • Made In Canada
    Single/Twin $152
    Twin XL In stock for fast delivery $203
    Double/Full In stock for fast delivery $206
    Queen $251
    Compare at $499
    King In stock for fast delivery $328
    Online availability icon In-Stock Only 7 left!
    In-Store availability icon On Display:
    Free delivery availability icon Free delivery to M5H 2N1 as soon as Tomorrow, Aug 4
    Pickup available icon Only Pickup available to
    M5H 2N1
    View Details

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Upgrade your sleep at National Mattress

Discover a mattress that transforms your sleep into a truly rejuvenating experience. We offer a wide variety of options to suit every sleep style and preference, ensuring a better night's sleep.

Why Choose Us?

  • Variety: From plush to firm, we have options for every body type and sleep style.
  • Quality: Trusted brands and top-notch materials for long-lasting comfort.
  • Sleep Trials & Warranties: Enjoy peace of mind with flexible trials and warranties.
  • Expert Advice: Get personalized recommendations from our sleep specialists.

Mattress Selection Includes

  • Memory Foam: Contours to your body for personalized comfort and pressure relief.
  • Hybrid: Combines responsive springs with foam for balanced support and comfort.
  • Innerspring: Provides firm support, bounce, and cooling airflow.
  • Latex: Hypoallergenic, eco-friendly, and exceptionally comfortable.
  • Adjustable Beds: Customize your sleep position for optimal comfort.
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