Sealy Mellbreak Ortho Plus Mattress reviewed

The Sealy Mellbreak Ortho Plus is a firm, double-sided 28cm spring mattress with a lumbar PowerPack, and at the time of writing (September 2026) a double costs £407.94 at Mattress Online’s regular price. Mattress Online describes it as the firmest model in Sealy’s Ortho Plus line and Mattressman grades its support Extra Firm, so it is built for back and front sleepers who want a hard, even surface for far less than the Posturepedic models in our Sealy comparison.

How the Mellbreak is built

The Mellbreak listing at Mattress Online gives the construction below. There is no foam layer, so the comfort comes from synthetic fibre fillings held in place by tufts on both faces.

Sizes and prices

Mattress Online lists five UK sizes plus a zip-and-link super king. The prices below are its regular prices; in its September 2026 sale it was charging between 7% and 9% less. The small double and the zip-and-link super king were out of stock when we checked on 28 September 2026.

The same mattress costs £489 in a double at Mattressman, which had no sale on it when we checked.

How firm is it, and who is it for?

We rate the Mellbreak 8 out of 10 for firmness, one step firmer than the Steeple and Grasmoor Ortho Plus models. It suits back and front sleepers and heavier adults who sink through softer tops. Side sleepers usually need more give at the shoulder and hip, and Mattress Online itself points buyers who want something softer to the Eaglesfield Ortho Plus.

Very firm is not the same as best for a bad back. A randomised trial of 313 adults published in The Lancet (Kovacs et al., 2003) found that people with chronic low-back pain had better pain and disability scores after 90 days on medium-firm mattresses than on firm ones. Buy the Mellbreak because you like a firm bed, not as a treatment.

Trial, guarantee and care

Mattress Online’s 100-night comfort trial is an exchange, not a refund. You buy one of its mattress protectors with the Mellbreak, sleep on it for at least 30 nights, and can then swap it for another mattress. Sealy’s guarantee terms give Sealy Classics mattresses such as Ortho Plus 5 years, two fewer than Posturepedic, rule out rolling or bending the mattress and make regular turning a condition of cover. The National Bed Federation’s Bed Advice care guide recommends alternating a rotation and a flip every week for the first three months of a two-sided mattress, then monthly. Mattress Online’s 1,460 customer reviews average 4.6 out of 5.

Where the Mellbreak fits in Sealy’s range

Sealy’s own Ortho Plus page currently lists the Grasmoor, Scafell and Baystone rather than the Mellbreak, which is sold by retailers including Mattress Online, Mattressman and The Sleep Shop. It shares the Ortho Plus recipe of PostureTech springs, EdgeGuard and a central PowerPack, and it has the lowest double price in our comparison of Sealy mattresses.