Rainscreen Principles are rooted in the understanding and design of exterior wall details that will provide an effective moisture-resistant surface applied to a sheathing. An air cavity between the sheathing and exterior panel allows for the drainage and evaporation of moisture. The rainscreen should effectively moderate the pressure differences between the cavity and the outside environment.
Employing an exterior cladding surface allows the forces of wind and wind-driven water such as rain and snow to lose its momentum. This is typically achieved by utilizing Ventilated or Conventional rainscreen design.
Three rainscreen principles utilized by the Ventilated Rainscreen Facade System are:
• First line of Defence
- Reduces the moisture load on cladding
- minimise rainwater passage into the wall
• Second line of Defence
- intercept water
- flashed, drained, vented air cavity + water-resistant membrane
• Air Barrier System–Ventilation Effect
- reduces the static air-pressure difference across the cladding, creating a “chimney effect.”
A Ventilated Rainscreen Facade System (VRFS), utilizes the BILDTEC substructure cladding system with an air cushion or cavity immediately behind the Panel. The cavity provides a drainage, ventilation and thermal solution.
The external cladding substructure system utilizes mechanical fastening to various substrates such as wood or metal structural framework, structural concrete block work, masonry walls or poured concrete walls. A layer of thermal insulation can be conveniently installed on the outer structural side of the substrate wall when applicable. Subsequently, the desired architectural façade material is fastened to the substructure utilizing the specified clipping system in conjunction with the BILDTEC’s structural adhesive PANEL-BOND, specifically designed for the installation of Porcelain Stoneware, Cement Board, Phenolic Composite Panels, Wood and Metal.
The architectural façade panels are fixed to the substrate wall by means of a lightweight substructure which is made of aluminum brackets, aluminum profiles, stainless clips and stainless fasteners.
Drainage and ventilation are facilitated by the specified cavity spacing and openings located at the top and bottom of the panels which is an integral part of the systems open joint design. This also allows a Chimney Effect to occur; thus allowing for the movement of air which contributes to the drying of any possible concentration, as well as the thermal exchange of cool and or warm air.
This ventilation allows for an exchange of air behind the panels, providing the solution for venting any moisture away and contributing to improved Heating and Cooling conditions inside the building. Installing the insulation on the outside face of the wall system along with an air/vapour barrier promotes the movement of the “Dew Point” to the outside surface of the structural wall assembly minimizing the development of condensation within the interior wall cavity.
BILDTEC's substructure systems can be used for a variety of cladding options:
Natural Stone - Granite, Limestone, Marble etc