What it costs: Suspended ceilings
- Date: 19/06/2009
Building Magazine: The many choices when specifying a suspended ceiling for a hospital are made more difficult by the regulations on cleaning and acoustics. Peter Mayer of BLP Insurance takes a look
Specifying a suspended ceiling for use in a hospital is a complex task. A glance at a few product catalogues reveals hundreds of variations in:
Lining or membranes - Systems may be demountable or fixed. Membranes come in different shapes including planks, tiles, panels or curved profiles in various sizes and thicknesses. Choices must also be made about edging, surface finishes and decorative finishes, to name but a few.
Vertical members - Suspension or hanger assemblies. These are generally metal rods, angles or wire
Horizontal members - Commonly aluminium or galvanized steel profiled to suit the tile for concealed, clip-in or lay-in systems
Accessories - Everything from fixings to the building structure, trim for perimeters, cut-outs, bulkheads, access hatches, additional support for services such as lighting or air-conditioning and fire breaks.
The choice is also, of course, influenced by the functional properties required and also the capital costs and future operational costs.
The starting point for hospital ceilings is the Health Technical Memorandum (HTM) 60, which defines six categories of ceiling performance. HTM 60 connects membrane performance to material options and the requirements of the hundreds of different activity spaces in hospitals. However, suspended ceilings also need to meet other functional requirements that have life-cycle cost implications.
Acoustic properties are an important consideration and are defined by HTM 2045. Observational surveys suggest that improved sound performance contributes to the quality of care provided and the well-being of patients. The sound absorption of suspended ceiling systems is determined by ISO 11654. Rating classes range from A to E, with class A systems providing the best absorption. Noise reduction coefficients and sound attenuation data may also be quoted.
Cleaning is another issue. Cleaning methods and frequencies are defined in the NHS Cleaning Manual and guidance on infection control. The physical qualities which ease cleaning, such as hard, smooth, glossy surfaces, are those that lead to poor acoustic performance. It is important to select membranes that do not compromise either requirement.
The European standard for suspended ceilings, EN 13964, requires that makers state whether or not the visible parts of the ceiling system are cleanable and how they may be cleaned. Quantitative proof of surface cleanability is not easy to come by. Performance in use is a guide, and BS EN ISO 11998 may be referred to for the determination of wet-scrub resistance and the cleanability of paint coatings. Some membrane systems incorporate surfaces that repel dust and dirt. The evidence for these claims should be confirmed for the expected use.
The easier the ceiling surface is to clean and the more resistant the surface is to accidental cleaning damage, the better the life-cycle cost performance.
Other functional and life-cycle cost issues include: resistance to loads and wind uplift, anti-bacterial and anti-mould properties, impact resistance, light reflectance and diffusion, environmental impact, capacity to be recycled, handling properties and factors influencing installation costs such as tile size and ease of cutting.
Service life considerations
Suspended ceilings are liable to a range of actions that may reduce their service life, the most typical include:
- Physical damage, usually to edges during handling or cleaning
- Leakage from services such as air-conditioning and water pipes
- Surface damage following handling with dirty and greasy equipment, gloves or hands
- The associated costs of intensive cleaning: decanting and protection might be greater than simply replacing the ceiling membranes, especially for demountable systems.
- Reorganisation or refurbishment may drive replacement.
BLP Insurance provides latent defect insurance for buildings, www.blpinsurance.com.