Stone Cladding Systems Ltd. supplies Natural Stone Rainscreen to the Construction Industry and we hope that we are able to help; assist and educate on the benefits of Stone Rainscreen. There are many reasons why stone is a very good choice for rainscreen and here we look at thermal Performance.
The thermal performance of a Natural Stone Rainscreen system refers to its ability to resist heat transfer and provide insulation as well as thermal stability to the external building envelope .
Ø Thermal Conductivity of Natural Stone: The excellent inherent thermal properties of stone plays a significant role in determining the overall thermal performance. This is closely related to Thermal Mass where the thickness and density of the stone cladding contributes to the overall thermal mass of the building. Thermal mass helps regulate indoor temperatures by absorbing and releasing heat slowly. Typically k-Values of 1.25-2.5 W/mK for Sandstones granite & limestone.
Ø Cavity Ventilation: The air gap between the outer stone layer and the building wall creates a ventilated cavity. This gap can help manage moisture and heat transfer. The airflow in the cavity can contribute to better thermal insulation, as the moving air creates an additional barrier to heat transfer. A wider cavity may provide better insulation due to the increased airspace for convective heat transfer.
The excellent thermal properties of stone play a significant role in overall performance
Ø Thermal Bridging: The presence of thermal bridges, which are areas of the assembly with higher heat conductivity, can negatively impact the thermal performance. These bridges can occur where structural elements like framing or support systems penetrate the insulation layer, allowing heat to bypass the insulation. Certain fixings are now available through Stone Cladding Systems and their partners Hilti Great Britain that vastly reduce this thermal bridging and allow a much reduced insulation thickness for a given U value. Useful for increasing the floor area !
Ø Orientation and Solar Radiation: The direction in which the building faces and its exposure to solar radiation can affect the thermal behavior of the rainscreen system. South-facing walls, for example, might experience higher solar heat gain for a given finish.
To assess the thermal performance of a specific natural stone rainscreen system, it’s important to consider factors such as stone type; insulation materials; cavity design/size; bracket design and overall building envelope design. Thermal modelling and analysis can be used to predict how these factors interact and the impact they have on the energy efficiency of the building. Stone Cladding Systems Ltd. and their partner Hilti Great Britain are here to help and would welcome any enquiry. Please do get in touch. sales@scs-stone.co.uk