What to remember: Cladding/curtain walling access

When specifying cladding and curtain walling, designers and specifiers are legally obliged to consider access for maintenance and repair.

Access to all parts of a building is required, which is no simple proposition, as different structures need different approaches. Balancing practical, economic, safety and legal issues is challenging, so a clear strategy must be developed from the start, when designing the structure.

The design depends on the materials, the complexity of facades and the exposure of the site. The specifier must establish how frequently access is needed and include this in the specifications.

Cladding material

Painted surfaces need regular cleaning as dirt can age the material prematurely. Glass must be cleaned periodically to avoid surface pitting and degradation.

Stone is mostly resilient but dirt can attack it. Terracotta and brick cladding rarely need maintenance, but should occasionally be inspected for damage.

Other elements, including sealants, flashings, fixings and cover plates, must be cleaned and examined regularly.

Most curtain walling systems have internal drainage systems, which need frequent inspection by experts.

Cleaning and inspection intervals

Requirements vary wildly. Specifiers should analyse the design and materials, and set out recommendations in the building handbook.

For average site exposure:

• Glass and metal curtain walling
Cleaning: every two months
Full inspection: twice a year

• Cladding systems
Cleaning: twice a year
Full inspection: every three years

• Brick and stone
Cleaning: once a year
Full inspections: every five years

Signs, light fittings, lighting conductors, and rainwater pipes should be inspected annually or, for critical items or exposed sites, twice a year.

Types of building

In apartment blocks the privacy of residents must be thought of – they may wish to be consulted before anybody has access.

In high-security buildings, access may be a risk, so special controls and authorisation may be required.

In retail buildings it is preferable that maintenance work does not interfere with opening times. Therefore, access systems should be hidden from entrances and public areas. Offices need access systems designed around the curtain walling system.

Generally, industrial buildings are less frequently maintained and have lower budgets than other buildings. As such, simple designs, which still fulfil safety and practicality demands, are needed.

The size and shape of the building must also be considered. Large buildings tendto be complex but often have big budgets and lots of space.

Practical issues of access

Access systems can be designed either around the ground, roof or intermediate floors.

Access from the ground is the most common and involves ladders, assembled platforms or mechanised plants.

Sufficient ground strength to support the equipment, and level space around the perimeter are essential. Ensure the pathway is big enough for a variety of different platforms so the building owner is not restricted. Stabilisation fixings for the equipment, particularly for ladders, must be considered.

Access from roof level consists of cradles, chairs and ropes. Cradles must be planned around cladding and need supporting structures at roof level, which must be included in the planning application drawings.

Access from upper floors is often limited but appropriately designed windows may help. Ensure that the code of practice BS 8213-1 for window cleaning and access is accommodated. Ensure operatives can latch onto safety fittings and that over-reaching is not required.

Specifiers must consider weather conditions. For exposed sites or buildings that need inspections in all weathers, procedures and systems must be particularly robust.

Check points

• Keep access in mind from the beginning of the project
• Develop access alongside the design
• Be aware of complex facades
• Large projects may require specialists
• Automated systems are available but expensive.