Serta Clarks Hill Plush Cal King Mattress - 11" Cooling, Supportive, Comfortable, CertiPur-US Certified California King Mattress for Restful Sleep

Product Overview

The Serta Clarks Hill Plush mattress measures 83.5 inches long by 72 inches wide by 11 inches thick in the California King size shown. It uses a hybrid construction with multiple foam layers over a pocketed coil support core. The comfort layer incorporates Cool Twist Gel Foam, where cooling gel is swirled into breathable foam to promote airflow and heat dissipation. Above this sits PillowSoft Foam, an extra-soft foam designed to gently contour to the body for enhanced cushioning. The support core contains 805 individually wrapped coils that feature Serta's Best Edge foam encasement technology. This extra-deep foam rail helps support the edges and extend the usable sleep surface. Beneath the coils, Serta Support Foam provides a base that balances cushioning and support. The mattress is not compressed into a box; it arrives as a traditional full-size mattress. The cover is made from a fabric blend. Care instructions recommend using a mattress protector to guard against stains and spills. For cleaning, apply baking soda to soiled areas, let stand for 15 minutes, vacuum, and repeat as needed. Liquids should not be applied directly as they may stain fabric and damage foam. The mattress is CertiPur-US certified, ensuring foam materials meet standards for content, emissions, and durability. It is designed for adult use and comes with model number 500703192-1070.

Design & Build

The Serta Clarks Hill Plush uses a layered hybrid construction. The top comfort layer combines Cool Twist Gel Foam and PillowSoft Foam. Cool Twist Gel Foam integrates cooling gel swirls into breathable foam to dissipate heat. PillowSoft Foam adds extra softness that contours gently to the body. These layers aim to provide pressure relief while keeping sleep surface cool. Below this, the support core contains 805 individually wrapped pocketed coils. Each coil moves independently to reduce motion transfer and offer responsive support. The coils are surrounded by Serta's Best Edge foam encasement, a deep foam rail that reinforces the mattress perimeter. This extends the usable sleep surface and improves edge support. A base layer of Serta Support Foam provides foundational stability. The mattress is 11 inches thick overall, giving substantial height for comfort and durability. The cover is a fabric blend that is breathable and soft to the touch. The mattress arrives as a traditional full-size unit, not compressed in a box. This eliminates the need for expansion and off-gassing time. Setup involves simply placing the mattress on a suitable foundation.

Care and maintenance are straightforward. Serta recommends using a mattress protector to guard against stains and spills. This also helps extend the mattress lifespan. For cleaning, apply baking soda to soiled areas, let stand for 15 minutes, then vacuum. Repeat as needed. Liquids should not be applied directly as they may stain the fabric and damage foam. The mattress should be aired out periodically. The materials are CertiPur-US certified, ensuring they meet standards for content, emissions, and durability. The construction is designed for adult use and long-term performance. The non-compressed delivery means the mattress retains its full integrity from day one. The design focuses on combining plush comfort with robust support through its hybrid approach.

Performance

Reviewers report mixed experiences with firmness and support. Some find the mattress provides excellent support without excessive sagging. One reviewer weighing 250+ pounds noted minimal motion transfer and firm support that helped with back pain. Another mentioned good edge support and no sagging after several months of use. The cooling gel foam is praised by some for maintaining a comfortable sleep temperature. However, other reviewers describe the mattress as uncomfortably firm. One side sleeper experienced shoulder pain due to lack of plushness. Another reported back pain regardless of sleep position. The plush designation may not match expectations for those seeking a soft surface. Motion isolation receives varied feedback. Some users note low motion transfer, while others report significant disturbance when a partner moves. The pocketed coils aim to reduce motion transfer, but results depend on individual sensitivity and weight distribution.

Durability and longevity show inconsistencies. Several reviewers mention the mattress holding up well with no sagging or lumps. One user appreciated the heavy-duty feel and expected long-term durability. Conversely, another reviewer reported developing lumps and sagging within six months. This suggests potential variability in construction or usage conditions. The edge support from the Best Edge foam encasement is generally seen as effective, extending the usable sleep surface. The mattress is described as quiet, with no noise from the coil system. Temperature regulation works adequately for most, especially with additional airflow from fans or AC. The non-compressed delivery means immediate performance without break-in time for expansion. Overall, the mattress performs well for those who prefer a firm, supportive feel with cooling features, but may disappoint sleepers seeking genuine plush comfort.