Building designers, specifiers and contractors working with external wall insulation systems (EWIS) have fresh technical guidance at their fingertips following the publication of the British Board of Agrément’s ‘Resistance to wind load’ literature.
The document examines potential issues created by poor system design and installation in relation to wind load resistance and offers guidance on addressing negative wind load, freeze-thaw, weather exposure and assessing the supporting structure/substrate prior to an EWIS installation.
“Recent reports of EWIS structural failures worldwide have raised technical bodies’ awareness regarding these systems’ resistance to wind loading,” states the literature. “The collapse of EWIS — which are often rendered with heavy finishes — from the external walls of high-rise buildings can cause property damage, serious injury and fatalities.
“Although the thermal performance is the most important feature for users, the structural stability of the system is often over-looked by the non-technical community. It is important when designing and specifying EWIS’s to consider every mechanism by which they resist applied static and dynamic loads.”
To emphasise the importance of structural integrity, the BBA has revised all current EWIS certificates in relation to strength and stability and is offering training on wind load resistance to certificate holders, suppliers and architects. The training provides technical guidance on understanding and applying design data in certificates; following the principles detailed on BBA certificates can provide a mechanism for satisfying Part A of the Building Regulations.
To download a copy of the BBA’s ‘Resistance to wind load’ click here.