Sealy Posturepedic Elevate Blackwood Mattress reviewed

The Sealy Posturepedic Elevate Blackwood is a 28cm firm, single-sided coil spring mattress with a firmer foam zone under the lower back and a 7-year Sealy guarantee. Mattress Online lists it from £779 in a single at its regular price.

Construction

According to the Blackwood page at Mattress Online, Sealy builds it on its AlignSupport coil unit, which is twice tempered and then held compressed for a week before assembly. Above the springs, a ComfortCore of firm and extra-firm foams supports the lumbar area, and reflex foam forms the comfort filling. UniCased edge support locks the spring unit in place and BasePlank forms the foundation.

Prices by size

At the time of writing (September 2026), Mattress Online lists all four UK sizes at these regular prices. In its September 2026 sale it was charging between about 7% and 17% less, with the biggest cut on the double.

Who it suits

Sealy and Mattress Online label the Blackwood firm, and we place it at 7 out of 10. The lumbar ComfortCore keeps the hips from dropping, which suits back sleepers and couples who want a stable surface. Lighter side sleepers may want more cushioning at the shoulder. The evidence on back pain favours a middle ground: a randomised trial of 313 adults published in The Lancet (Kovacs et al., 2003) found that after 90 days, people on medium-firm mattresses had better results for pain in bed (odds ratio 2.36) and disability (2.10) than those on firm ones.

For allergy sufferers, the Allergy UK product listing for Sealy includes the Posturepedic Elevate collection among the Sealy ranges with its Seal of Approval, based on the ProShield or Purotex ticking.

Trial, guarantee and delivery

Mattress Online offers a 100-night comfort trial as an exchange, not a refund, and only when you buy one of its mattress protectors with the mattress; you are asked to sleep on it for 30 nights first. The Sealy guarantee terms give Elevate mattresses 7 years, claimed through the retailer. The Blackwood is single sided, so it only needs rotating, which the National Bed Federation’s Bed Advice care guide suggests doing weekly for three months and monthly after that.