Firm Sinca® Adjustable Bed Base Friendly All

Firm mattresses give you the most support of our everyday comfort levels — a solid, stable surface that keeps your spine aligned instead of sinking in. Firm is the go-to for back and stomach sleepers, heavier-weight sleepers who need extra support, and anyone looking for orthopedic, back-friendly comfort; side sleepers or those who like a softer feel may prefer our medium or plush options. Choose from tight-top, foam, euro-top and hybrid builds across Sealy, Serta, Beautyrest, Stearns & Foster, iComfort, Tempur-Pedic, Chirofoam and our own NM line — from budget-friendly models at $59 to premium, with free delivery across Canada. • Feel: firm gives a solid, supportive surface with minimal sink-in • Best for: back and stomach sleepers, heavier-weight sleepers, and orthopedic / back-pain support • Consider softer if you sleep on your side or want more cushioning — see our medium or plush options • Constructions: tight-top (most firm beds), foam, euro-top and hybrid • Brands: Sealy, Serta, Beautyrest, Stearns & Foster, iComfort, Tempur-Pedic, Chirofoam, Springwall & NM • Prices: from $59 (budget) to premium — our widest price range • Want the firmest feel? See our extra-firm mattresses
Sinca metal bed frames give any mattress a solid, squeak-free foundation. Built from heavy-gauge steel with adjustable widths to fit twin through king, they set up in minutes with no tools and carry a lifetime limited warranty. A practical, long-lasting base for boxspring-and-mattress sets.
Shop adjustable base friendly mattresses from Beautyrest, Serta, Sealy, Tempur-Pedic, Springwall, iComfort, and Stearns & Foster at National Mattress — 169+ models in memory foam, hybrid, latex, eurotop, and tight-top constructions from $59 to $6,640. Every mattress in this collection is manufacturer-verified to flex and articulate with an adjustable base without voiding the warranty. Available in Twin through King sizes with firmness levels from extra firm to plush, all built with CertiPUR-US® certified foams, including Canadian-made options. Free delivery is available, along with a 365-night sleep trial and 5–15 year warranty coverage.

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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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Thousands in Stock

We have over 1,000 mattresses in stock.

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