Sealy PosturePedic Gladesville Combination King Size Mattress
The Sealy PosturePedic Gladesville Combination Mattress pairs a plush EternityFibre comfort layer with an extra-firm feel, which means you get a very supportive bed with a slightly softer surface on top.
- Extra-firm feel for firm-bed sleepers
- Plush fibre layer softens the surface
- Allergy UK endorsed cover
£1,599
Get the lowest price we've found
Save with the previous model
Some retailers still sell the earlier version of this mattress for less than the current model's best price.
Sealy PosturePedic Gladesville Combination Mattress
More available sizes
Mattress details
Mattress
Sealy PosturePedic Gladesville Combination Mattress
Size
Firmness
Extra Firm
Construction
Eco-Friendly
Foam
Depth (cm)
27
Layers
3
Layer Details
EternityFibre
A plush fibre comfort layer that Sealy says adds cushioning and a softer surface. It gives the top of this extra-firm mattress a little more comfort.
INFUSE Eco ComfortCore
A plant-based foam that forms part of the mattress. Sealy doesn't state where it sits in the build, but it adds a plant-based material to the construction.
AlignSupport coils
Patented coils that form the base of the mattress. They provide the firm, supportive feel this mattress is rated for.
Layer details from dreams.co.uk product page, November 2026.
Key benefits
- More room each: At 75cm each for two sharing, you get 7.5cm more than on a UK double, which means fewer nudged elbows when your partner rolls over in the night.
- Length for a taller partner: The UK king is 200cm long and 10cm longer than a UK double, so a partner over six foot is less likely to end up with their feet at the very edge.
- Space for different body clocks: If one of you is up hours before the other, the extra width puts a little more distance between you as they get out of bed in the dark.
- A dependable edge on each side: Sealy's UniCased edge support aims to give a dependable edge, which helps if injury or surgery means you sit on the side before standing up.
- The same firm feel for both of you: The extra firm rating runs across the full UK king, which suits most back and front sleepers, although a lighter side sleeper may find it unyielding at the shoulders.
This size suits you if...
You share a bed every night and keep disturbing each other on a UK double, one of you is tall enough to need the 200cm length, and you both prefer a properly firm, extra firm mattress.
Consider another size if...
Your bedroom measures less than 2.7m x 2.9m once the wardrobes are in. We'd recommend the UK double instead, which needs at least 2.6m x 2.8m.
Similar Mattresses in This Price Range
Did you know? On Mattress Unboxed we have over 1,000 different mattresses to suit all types of sleepers. View all mattresses.
FAQ's
How much space does each person get on the Sealy Gladesville UK king?
Two people sharing the UK king get 75cm each. That's 7.5cm more each than on the UK double, which gives 67.5cm each. If you want more than that, the UK super king gives 90cm each, so the UK king gives 15cm less each than the super king.
Is the Sealy Gladesville UK king long enough for someone over six foot?
The UK king is 200cm long, 10cm longer than the UK double, and that extra length is often why taller couples size up. The UK super king is the same length as the UK king, so moving up to a super king gives you more width but no extra length.
What size bedroom do I need for a UK king Sealy Gladesville?
We suggest at least 2.7m x 2.9m, and 3.2m x 3.2m is more comfortable. New build master bedrooms can feel smaller once fitted wardrobes and bedside tables are in, so measure the floor you'll actually have left, not the room's total dimensions.
Sealy Gladesville UK king or UK super king for a couple who wake each other up?
The UK super king gives 90cm each against 75cm on the UK king, so it puts more distance between you. It needs more room though: we suggest at least 3m x 2.9m for the UK super king, compared with at least 2.7m x 2.9m for the UK king.
What bedding fits the Sealy Gladesville in a UK king?
Standard king sheets and a 230 x 220cm king duvet fit the UK king. The mattress is 27cm deep, so check that your fitted sheet's pockets are deep enough to tuck under properly before you order a new set.