Sealy
Comparison
Compare Firm Mattresses UK 2026
Firm mattresses can use very different support systems. This table puts verified construction, price, depth, trial and warranty information side by side.
Our Quick Answer
This table compares four mattresses currently recorded as firm in the catalogue: Silentnight, Sealy, Sleepeezee and The Sleep Co. The comparison is specification-led and does not declare a winner.
All four are recorded as firm
The constructions include open-coil and pocket-sprung designs
Current verified prices are shown where available
No missing figure is estimated
Comparison
Verified Side-by-Side Table
This table uses current published products and verified information stored in our catalogue. Category comparisons update automatically as eligible products are added or removed. Missing information is intentionally left blank rather than estimated. Prices and retailer terms can change, so check the retailer before buying.
Silentnight
Silentnight Ortho Dream Star Miracoil Mattress
Sleepeezee
Sleepeezee Deluxe 1000 Pocket Mattress
The Sleep Co
The Cavendish Natural Firm
From price
Sealy
Sealy Mellbreak Ortho Plus Mattress
£308
Silentnight
Silentnight Ortho Dream Star Miracoil Mattress
£233
Sleepeezee
Sleepeezee Deluxe 1000 Pocket Mattress
£298
The Sleep Co
The Cavendish Natural Firm
£1,099
Single price
Sealy
Sealy Mellbreak Ortho Plus Mattress
£308
Silentnight
Silentnight Ortho Dream Star Miracoil Mattress
£233
Sleepeezee
Sleepeezee Deluxe 1000 Pocket Mattress
£298
The Sleep Co
The Cavendish Natural Firm
£1,099
Double price
Sealy
Sealy Mellbreak Ortho Plus Mattress
£418
Silentnight
Silentnight Ortho Dream Star Miracoil Mattress
£317
Sleepeezee
Sleepeezee Deluxe 1000 Pocket Mattress
£394
The Sleep Co
The Cavendish Natural Firm
£1,299
King price
Sealy
Sealy Mellbreak Ortho Plus Mattress
£458
Silentnight
Silentnight Ortho Dream Star Miracoil Mattress
£373
Sleepeezee
Sleepeezee Deluxe 1000 Pocket Mattress
£498
The Sleep Co
The Cavendish Natural Firm
£1,349
Super King price
Sealy
Sealy Mellbreak Ortho Plus Mattress
£574
Silentnight
Silentnight Ortho Dream Star Miracoil Mattress
£457
Sleepeezee
Sleepeezee Deluxe 1000 Pocket Mattress
£564
The Sleep Co
The Cavendish Natural Firm
£1,449
Mattress type
Sealy
Sealy Mellbreak Ortho Plus Mattress
Open Coil
Silentnight
Silentnight Ortho Dream Star Miracoil Mattress
Open Coil
Sleepeezee
Sleepeezee Deluxe 1000 Pocket Mattress
Pocket Sprung
The Sleep Co
The Cavendish Natural Firm
Pocket Sprung
Firmness
Sealy
Sealy Mellbreak Ortho Plus Mattress
Firm
Silentnight
Silentnight Ortho Dream Star Miracoil Mattress
Extra firm
Sleepeezee
Sleepeezee Deluxe 1000 Pocket Mattress
Firm
The Sleep Co
The Cavendish Natural Firm
Firm
Depth
Sealy
Sealy Mellbreak Ortho Plus Mattress
28 cm
Silentnight
Silentnight Ortho Dream Star Miracoil Mattress
22 cm
Sleepeezee
Sleepeezee Deluxe 1000 Pocket Mattress
The Sleep Co
The Cavendish Natural Firm
28 cm
Sizes
Sealy
Sealy Mellbreak Ortho Plus Mattress
Single, Small Double, Double, King, Super King
Silentnight
Silentnight Ortho Dream Star Miracoil Mattress
Single, Small Double, Double, King, Super King
Sleepeezee
Sleepeezee Deluxe 1000 Pocket Mattress
Single, Small Double, Double, King, Super King
The Sleep Co
The Cavendish Natural Firm
Single, Small Double, Double, King, Super King
Sleep trial
Sealy
Sealy Mellbreak Ortho Plus Mattress
100 nights
Silentnight
Silentnight Ortho Dream Star Miracoil Mattress
100 nights
Sleepeezee
Sleepeezee Deluxe 1000 Pocket Mattress
The Sleep Co
The Cavendish Natural Firm
90 nights
Warranty
Sealy
Sealy Mellbreak Ortho Plus Mattress
5 years
Silentnight
Silentnight Ortho Dream Star Miracoil Mattress
5 years
Sleepeezee
Sleepeezee Deluxe 1000 Pocket Mattress
The Sleep Co
The Cavendish Natural Firm
15 years
Product information
Key features
Sealy
Sealy Mellbreak Ortho Plus Mattress
- PostureTech Core Support springs
- Soft white fibre comfort layer
- Edge support
- Double-sided construction
- 28cm depth
Silentnight
Silentnight Ortho Dream Star Miracoil Mattress
- Miracoil spring support system
- Eco Comfort Fibre layer
- Extra-firm feel
- 22cm depth
Sleepeezee
Sleepeezee Deluxe 1000 Pocket Mattress
- 1,000 pocket springs
- Soft white fibres
- Firm feel
The Sleep Co
The Cavendish Natural Firm
- 6,405 individually pocketed springs
- 50mm natural latex
- Wool, cotton, silk, cashgora and horsehair fillings
- Three rows of hand side stitching
- Made in Britain
Product details
Sealy
Sealy Mellbreak Ortho Plus Mattress
A firm traditional sprung mattress using Sealy's PostureTech Core Support system, soft white fibres and reinforced edge support.
Silentnight
Silentnight Ortho Dream Star Miracoil Mattress
An extra-firm orthopaedic-style sprung mattress using Silentnight's Miracoil support system and an Eco Comfort Fibre comfort layer.
Sleepeezee
Sleepeezee Deluxe 1000 Pocket Mattress
Firm pocket-sprung mattress with soft white fibre comfort fillings.
The Sleep Co
The Cavendish Natural Firm
British-made firm natural mattress with 6,405 individually pocketed springs, 50mm natural latex, hand-layered natural fibres and three rows of hand side stitching.
Current product page
The Essentials
What Really Matters
Construction
The table distinguishes open-coil and pocket-sprung designs rather than treating every firm mattress as equivalent.
Depth
Verified mattress depth is shown where available and left blank where it is not.
Price
Only current verified stored prices are displayed.
Buying Advice
How to Choose the Right Mattress
Firmness is not universal
A manufacturer or retailer firmness label is shown as supplied in the verified catalogue. Personal perception can still vary.
Our Tip
Missing information is deliberately left blank in the comparison table rather than estimated.
Checklist
Before You Buy
Check the current price for your exact mattress size
Read the full sleep-trial and warranty terms
Confirm delivery, collection and recycling arrangements
Use the manufacturer or retailer product page for any specification not shown in the table
Questions
Frequently Asked Questions
No. These products use different spring systems, depths and materials even though they are all recorded as firm.
No. It is a factual specification comparison rather than a ranking.
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Evidence
Sources & Evidence
Mattress Online · checked 20 Sept 2026
Mattress Online · checked 20 Sept 2026
Mattress Online · checked 20 Sept 2026
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