XPS 700

Extruded Polystyrene Insulation be used in many applications. Unilin provide XPS for floors, roofs and wall applications as it is ideally suited for use in highly loaded and trafficked floors, basement walls and inverted roofs.

R-value

A low lambda value(Thermal conductivity) results in a high R-value or thermal resistance, a measure by which we assess specific insulation products in relation to their insulation thickness. This thermal resistance quantifies the area and temperature difference needed to transfer 1W of heat energy. The higher the R-value, the lower the amount of heat loss.

The low lambda value of XPS means that anyone working with the product can insulate a building comfortably thanks to its thickness while optimising the energy performance. With XPS, you can make efficient use of the space available to you. Since you need less insulation material overall, this is the definition of a smart investment

A U-Value measures the rate of heat transfer through a building element, such as a roof, wall, window, door, or floor. In building physics, it represents the thermal transmittance of a construction assembly and is defined as the inverse of the total thermal resistance (R-value) of all layers within that element.

In simple terms, the U-Value indicates how much heat flows through a material or structure from a warm area to a colder area. It is a key metric used to evaluate the thermal performance and energy efficiency of building components.

Heat naturally moves from warmer spaces to cooler ones. The U-Value quantifies the amount of heat lost or gained through a building component per unit area for each degree of temperature difference across it.

W/m²K (watts per square metre kelvin)

This unit describes how many watts of heat pass through one square metre of a structure for every 1-degree temperature difference between the inside and outside environments.

Example of a U-Value: A wall panel with a U-Value of 0.15 W/m²K means that 0.15 watts of heat will transfer through each square metre of the wall for every 1°C difference between indoor and outdoor temperatures.

Factors That Affect U-Values

Several factors influence the U-Value of a building element, including:

• Type of insulation material
• Thickness of insulation layers
• Density and thermal conductivity of materials
• Air gaps or cavities within the construction
• Thermal bridges caused by structural elements
• Surface resistances and material finishes

Optimising these factors helps reduce heat loss and improve overall building performance.