Simba TripleShield Tencel Cool Mattress Protector reviewed

The Simba TripleShield Tencel Cool Mattress Protector is a thin, waterproof fitted protector with a 100% Tencel top fabric, polyester back and skirt, sized for mattresses up to 40cm deep. Simba sells it as the coolest of its three protectors; it adds no padding, so it protects the mattress without changing how it feels.

Specification

Specifications are taken from the Simba product page. Tencel is a branded lyocell fibre made from wood pulp; Simba chose it because it wicks moisture and breathes, which is the main thing a warm sleeper notices on a waterproof protector.

How waterproof is TripleShield?

Simba says the TripleShield layer is waterproof and meets the BS EN ISO hydrostatic-head requirement, the standard fabric test that measures how much water pressure a fabric withstands before it leaks. That method is now published in the UK as BS EN ISO 811:2018. The Tencel page’s technical block quotes a minimum of 1,500mm but names the Bamboo model in the same sentence, an apparent copy-and-paste slip, so we treat the exact figure as confirmed for the Bamboo version only. In the coffee spill test for its June 2026 review, Expert Reviews found that none seeped through the top layer, and the protector stayed silent when the reviewer moved on it.

Temperature

A protector cannot cool a room, but it can avoid trapping heat. The Sleep Charity recommends a bedroom of around 16 to 18°C and says above 24°C restlessness becomes likely; a light, breathable top such as Tencel helps most when the room is already close to that range. In the Expert Reviews test, the reviewer’s husband, who runs warm, said it kept him cool through the night.

Prices by size

Regular prices were checked on simbasleep.com on 28 September 2026, when the UK single was sold out and every other size was in stock. Simba was showing 25% off its protectors at the time, with no end date stated. The Tencel costs more than the otherwise similar Bamboo model in every size.

Simba’s three protectors side by side

Review counts are those shown on simbasleep.com on 28 September 2026. The Tencel and Bamboo models share the TripleShield waterproof construction and the 40cm anti-slip skirt; the difference you pay for is the top fabric.

Delivery and returns

Delivery is free to most of the UK, next working day when ordered before 1pm. Protectors are not covered by Simba’s 200-night mattress trial; they fall under its 30-day return policy for non-mattress items, with the original packaging. No guarantee period is published for the protector.