Firmness
Medium Firm
Type
Latex
Depth (cm)
29
Number of Layers
3
Trial Period (nights)
100
Warranty (years)
5
Price Range
£464 to £858
Best Sleeping Position(s)
Certifications
Assessed from the specification published by Mattress Online, captured September 2026, and from regular price comparison across our UK retail partners.
Latex is the main draw here. It responds to your body shape rather than slowly sinking like memory foam, which means pressure relief without that stuck-in feeling, and it tends to sleep cooler too. Underneath, Sealy's PostureTech springs use varied tensions to support the whole body, so heavier areas like hips get firmer resistance while shoulders sink in a touch more. The quilted sleep surface adds a soft first impression before you reach the firmer support beneath. It carries a 5-year guarantee, and buying through Mattress Online gets you a 100-night trial and free delivery to most locations, with a £20 charge if you want it carried to your room.
Key Features & what's inside
- Quilted sleep surface. A plush quilted top adds the final touch of comfort. This gives the mattress a softer initial feel before you reach the firmer layers below.
- Latex. A plush, adaptive material that responds to your body shape for individualised comfort. It contours without the slow sink of memory foam, which means easier movement and a cooler sleep.
- PostureTech Core Support Springs. Sealy's own spring design uses unique shapes and varied tension to deliver full-body support and pressure relief. In practice this means firmer resistance where you carry more weight, so your spine stays better aligned.
Layer details from mattressonline.co.uk product page, September 2026.
Who's it NOT for?
If you sleep on your side and are on the lighter side, the medium to firm feel may press a little too hard at the shoulders and hips. Fans of a deep, enveloping memory foam hug should also look elsewhere, as latex sits you more on the surface than in it.
Sealy Waltham Latex Advantage Mattress
Across owner reviews on mattressonline.co.uk, customers report comfortable sleep with a firm yet yielding feel and good material quality, and it particularly suits those with back issues. Impressions of firmness do vary, with some finding it softer than expected and others describing it as perfectly firm.
How firm is the Sealy Waltham Latex Advantage mattress?
Sealy describes it as medium to firm. Owner feedback is a little mixed, with some finding it softer than expected and others calling it perfectly firm, so expect a supportive feel with some surface give from the latex and quilted top rather than an outright hard mattress.
Does the Sealy Waltham come with a trial period?
Mattress Online lists a 100-night trial with this mattress. That trial is the retailer's own offer rather than a Sealy guarantee, so check the terms if you buy elsewhere. The mattress itself carries a 5-year guarantee.
How deep is the Sealy Waltham Latex Advantage?
It's 29cm deep, so most standard fitted sheets should still fit, though it's worth checking deep-fitted sizing if your sheets tend to run snug.
What sizes does the Sealy Waltham Latex Advantage come in?
Five UK sizes: Single, Small Double, Double, King and Super King, priced from £464 to £858 depending on the size you choose.
Does the Sealy Waltham mattress have handles?
The listing states turning handles are included, but some customer reviews mention an absence of handles for rotation, a discrepancy noted on the retailer's page itself. If handles matter for you, it's sensible to confirm with the retailer before ordering.
Couldn't find an answer to your question? Send us a message