What is a precast facade panel?
A precast facade panel is a reinforced concrete wall unit made at the plant to form the external wall of a building and fixed to a precast frame of columns and beams. In industrial buildings, the envelope that closes in the skeleton of columns, beams and roof trusses is most often formed with these panels.
Its role in an industrial building
Facade panels enclose the building against the weather, transfer wind loads to the columns they are fixed to and form a fire-resistant external wall. Panels can be stacked horizontally between columns or set vertically. In buildings that store bulk materials such as grain, fertiliser or sand, the lower panels are designed for the lateral pressure of the stored material and also act as retaining walls.
Panel types
Single-leaf solid panels are used in warehouses and industrial buildings that need no thermal insulation. Where insulation is required, sandwich panels with an insulation board between two concrete leaves are preferred. Door, window and ventilation openings are formed during production at the positions and sizes given in the design. Panel length, thickness and reinforcement are set by structural design according to column spacing, wind load and any additional loads the panel will carry. The face can be finished smooth, patterned or textured.
Production
Panels are cast in flat steel moulds once the reinforcement and cast-in parts are in place. Plates for the column connections, lifting anchors and formers for openings are fixed in position before casting. Once cured, panels are checked for dimensions, surface finish and the position of cast-in parts before going to the stockyard.
Delivery and erection
Panels are transported on suitable stillages and lifted by crane onto the connection points on the columns. The joints between panels are sealed with a sealant suited to external use, making the wall weathertight. Panels made in the same plant as the structural frame allow connection details to be designed to fit from the outset and erection to continue with the same crew.
Fire and durability
Concrete is non-combustible, so precast facade panels are well suited to external walls that limit the spread of fire and to fire compartment walls inside a building. The panels withstand impacts from forklifts and vehicles and need no painting or corrosion maintenance. In storage and production buildings especially, these qualities reduce maintenance over the life of the structure.