ULTCOVER Waterproof Square Hot Tub Spa Cover for 90" x 90" – Black 600D Polyester, Vented Elastic Fit

ULTCOVER's 90-inch waterproof square spa cover is a heavy-duty polyester outer layer designed to shield a square hot tub up to 90" on each side when used over an insulated hard cover.

This cover is an exterior weather barrier made from 600D polyester with a waterproof backing. It is intended to be slipped over an existing insulated hard cover to protect against rain, snow, leaves and UV exposure. Built-in vents, reinforced seams and adjustable elastic cords help keep the cover secure and breathable, preserving the condition of the underlying cover and the spa cabinet.

How does this cover protect my hot tub outdoors?

The ULTCOVER waterproof layer blocks water, debris and sunlight from reaching the insulated hard cover beneath, extending the life of that primary cover and reducing cleaning. Its 600D polyester face and waterproof backing form a durable shell, while full coverage design minimizes sun fading and surface damage.

• Waterproof 600D polyester with sealed backing repels rain and snow
• Full-coverage fit reduces UV exposure and keeps the area looking clean
• Prevents leaves, dust and bird droppings from accumulating on the hard cover

Will the cover stay put in wind and bad weather?

Yes. The cover includes heavy-duty elastic cords around the perimeter for a snug fit and structured side vents that allow airflow while preventing lift. These features work together to reduce flapping and displacement during gusts without trapping moisture against the underlying cover.

• Elastic adjustment cords tighten the skirt for stability in strong winds
• Dual structured air vents on the sides provide ventilation and reduce billowing
• Reinforced seams and construction improve resistance to tearing

What size and compatibility information should I know?

This model is sized to fit square hot tubs up to 90" long by 90" wide. It is designed exclusively as a protective outer layer and must be used in combination with a separate insulated hard cover — it is not a standalone insulating solution.

• Fits square spa tops measuring up to 90" x 90"
• Designed to slip over an existing insulated hard cover only
• Not suitable as a single insulating cover or replacement for a hard cover

How do I care for and maintain this cover?

Cleaning is simple: brush off loose debris and hose the surface; mild soap can remove stains. Store the cover dry and folded when not in use for long stretches, and check elastic cords and vents periodically for wear to maintain secure, breathable protection.

• Hose down or wipe with mild soap for routine cleaning
• Allow to dry fully before storing to prevent mildew
• Inspect cords, vents and seams seasonally for needed repairs

Who is this for? This ULTCOVER accessory is for hot tub owners who already have a rigid, insulated spa cover and want an extra layer of defense against weather, debris and sun damage. It's especially useful for properties exposed to heavy rain, snow, falling leaves or frequent bird activity, and for anyone seeking a low-maintenance means to preserve the appearance and lifespan of their primary spa cover.