Cladding for buildings
Cladding is the visible external finish of a building, such as the roof or external walls. Cladding is often pre-fabricated in panels that are attached to the structural frame of the building, and some cladding systems can be purchased 'off the shelf'.
Some definitions suggest that cladding is a non-structural external finish, as opposed to a load-bearing external construction. However, cladding can play a structural role transferring wind loads, impact loads and self-weight back to the structural framework. In particular, wind causes positive and negative pressure on the surface of buildings and so cladding must be designed to have adequate strength and stiffness to resist this load, both in terms of the type of cladding selected and its connections back to the structure.
Cladding is needed to:
- Create a controlled internal environment.
- Protect the building from external conditions.
- Provide privacy and security.
- Prevent the transmission of sound.
- Provide thermal insulation.
- Create an external facade.
- Prevent the spread of fire.
- Generate an 'airtight' building envelope.
- Providing openings for access, daylight and ventilation.
The nature of cladding selected for a particular building will depend on issues such as:
- How the building is going to be used.
- Internal and external conditions.
- Local context.
- Planning requirements.
- Maintenance requirements.
- Structural requirements.
High-quality, well-designed, properly-installed cladding can help maximise thermal performance, minimise air leakage, and optimise natural daylighting. This can help reduce the need for mechanical and electrical building services, and so improve energy efficiency and lower capital and running costs.
- Design detailing.
- Control of air leakage.
- Control of condensation.
- Integrity and continuity of Insulation.
- Control of thermal movement.
- Ease of installation.
- External attachments and fixings.
- Maintenance, remedial work and renewal.
- Resilience, strength and durability.
|H13||Structural glass assemblies|
|H14||Precast concrete and glass lens / paver rooflights / floor lights / pavement lights / security panels|
|H20||Rigid sheet cladding|
|H30||Fibre cement profiled sheet cladding / covering|
|H31||Metal profiled / flat sheet cladding / covering|
|H32||Plastics profiled sheet cladding / covering|
|H40||Glass fibre reinforced concrete panel cladding / components|
|H41||Glass fibre reinforced plastics cladding / features|
|H42||Precast concrete panel cladding / features|
|H43||Metal composite panel cladding / features|
|H51||Natural stone slab cladding / lining / features|
|H60||Plain roof tiling|
|H61||Fibre cement slating|
|H64||Wood shingle and shake roofing|
|H65||Single lap roof tiling|
|H67||Metal single lap roof tiling|
|H71||Lead sheet coverings / flashings|
|H72||Aluminium strip / sheet coverings / flashings|
|H73||Copper strip / sheet coverings / flashings|
|H74||Zinc strip / sheet coverings / flashings|
|H75||Stainless steel strip / sheet coverings / flashings|
|H90||Tensile fabric coverings|
Some of the more common types of cladding are described below.
Curtain wall systems are a non-structural cladding systems for the external walls of buildings. They are generally associated with large, multi-storey buildings. Typically curtain wall systems comprise a lightweight aluminium frame onto which glazed or opaque infill panels can be fixed. These infill panels are often described as 'glazing' whether or not they are made of glass.
See Curtain wall systems for more information.
The term ‘patent glazing’ refers to a non-load bearing, two-edge support cladding system. Patent glazing bars provide continuous support along two edges of glazing infill panels (rather than four-edge curtain walling), and are fixed back to the main structure of the building. This system supports its own weight, and provides resistance to wind and snow loading, but does not contribute to the stability of the primary structure of the building.
See Patent glazing for more information.
A rainscreen (sometimes referred to as a ‘drained and ventilated’ or ‘pressure-equalised’ façade) is part of a double-wall construction. The rainscreen itself simply prevents significant amounts of water from penetrating into the wall construction. Thermal insulation, airtightness and structural stability are provided by the second, inner part of the wall construction.A rainscreen (sometimes referred to as a ‘drained and ventilated’ or ‘pressure-equalised’ façade) is part of a double-wall construction. The rainscreen itself simply prevents significant amounts of water from penetrating into the wall construction. Thermal insulation, airtightness and structural stability are provided by the second, inner part of the wall construction.
See Rainscreen for more information.
One of the most popular methods of cladding is through the use of timber softwoods, such as western red cedar. This type of wood is relatively knot-free and has a natural resistance to decay and moisture. It can be readily stained or painted and altered to create a range of profiles. Western red cedar is generally sourced from North America (predominantly Canada), but it is starting to be grown in the UK. Other softwoods that are often used include Douglas fir and Scottish and Scandinavian larch.
Hardwoods can also be used including oak and sweet chestnut. Both of which contain high tannin levels which can result in leaching and streaking after exposure to the elements. Hardwood cladding also requires pre-drilling which can add to installation time and costs.
Thermally modified timbers are also being used such as Kebony, Keywood, Platowood and ThermoWood. The softwoods are heated to high temperatures which removes moisture and resins, resulting in a stable and durable material.
A fabric membrane is 'stretched' to form a three-dimensional surface that may be used to create a roof, shading, or decorative component. Sometimes described as 'modern tents', fabric structures use very little material compared to other forms of construction, and are typically translucent, but they provide little thermal mass or insulation and can have a shorter lifespan than some materials.
See Fabric structures for more information.
See Bricks for more information.
 Tile hanging
The traditional method of cladding a property is through the use of tiles. The addition of which can add character to older style properties.
 Shakes and shingle
Shakes and shingles are produced from split logs and look similar to timber tiles. Shakes are typically split from the log using a chisel and mallet whilst shingles are sawn off.
One of the cheaper forms of cladding is PVCu with white being the cheapest option. It often has fewer detailing requirements than timber and requires less maintenance, although it can discolour with age.
 Related articles on Designing Buildings Wiki
- Architectural styles.
- Building fabric.
- Curtain wall systems.
- Curved glass.
- Kinetic facade.
- Patent glazing.
- Thermal bridge.
- Wall types.
 External references
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