What Is High-Density Foam?

High-density foam is a compact, firm foam that offers greater strength, durability, and insulation properties than low-density foam. Because of its tightly packed cells, it provides:

• Superior thermal insulation — helps keep bath water warmer for longer

• Enhanced structural support — adds rigidity and durability to the bathtub shells

High-density foam is ideal for bathtub cavity walls because it combines comfort with long-lasting performance.

Why SanSiro Freestanding Tubs have Dense Foam Insulation Applied

At Sansiro, the tubs are designed and built to last a lifeltime. There are two primary reasons we dense foam insulate both cavity walls of the inner and outer shells of our bathtubs:

1. Water Temperature – Comfort and Energy Efficiency

During colder weather, the air trapped in the cavity between the tub walls is often cooler than your bathwater. While most heat loss occurs through the water surface, this cooler air can still draw warmth from the tub, making the bath feel less inviting over time.

By applying dense foam insulation to both cavity walls, we prevent colder air from penetrating either from the outside or from underneath. This keeps the inner surface of the tub warmer to the touch and helps retain the water temperature longer—resulting in a more comfortable, longer soak and reduced energy usage.

2. Enhanced Structure and Solid Feel

Our tubs are already built to high standards using thick acrylic reinforced with fiberglass and resin. Adding dense foam insulation further enhances this construction. It gives SanSiro tubs a more solid, premium feel. The insulation also adds structural support and rigidity, improving the overall strength and durability of the bathtub.