Wall finishes are crucial in healthcare buildings, where high demands are placed on durability. Peter Mayer of Building Performance Group sets out guidelines on whole-life costing
Healthcare buildings are large and complex with high movement rates of people and equipment. Designers have a tough job specifying materials and components that have to withstand wear, tear and accidental damage and meet standards for fire, noise, health and safety and accessibility. These items also have to meet NHS agendas of sustainability, improving patients’ experience, reduction of infection and waste reduction. So it’s no surprise that the whole-life approach is used to manage the design process and component selection.
The condition and appearance of wall finishes are key because they influence the feeling of space and light in healthcare buildings. It’s also been suggested that good design and colour may have a positive therapeutic effect with potential cost benefits such as improved patient recovery times. As large hospitals may have thousands of square metres of wall surface it is important to make the right choices both in terms of capital and in use costs.
Wall finish options
NHS Estates Health Technical Memorandum (HTM) 56 for Partitions details six performance categories for wall finishes based on water resistance, moisture resistance (relative humidity), jointing, smoothness
and tolerance to cleaning regimes. It also lists 18 wall finish options. Wall finishes recommended for circulation spaces are in performance category 5 and include: emulsion, oil or vinyl paints, paper backed vinyl and spongeable wallpaper. The more paints or wallcoverings are able to withstand cleaning, the longer the time between replacements or redecorations and the lower the whole-life costs.
The durability of a painted surface is in part related to the dry film thickness and its ability to withstand cleaning. BS 7719 is the British Standard for water-borne emulsion paints and defines three categories of paint based on a “scrubbing” test. Type A is for general use, B for areas of low wear such as ceilings and C for highly trafficked areas and should be specified for hospital circulation areas.
An alternative test is BS EN ISO 11998, which determines the wet-scrub resistance and cleanability of coatings. Five classes are defined with class 1 giving the best performance.
Wall coverings to BS EN 233 may be washable, extra washable or scrubbable. For more demanding areas with heavy pedestrian traffic heavy duty wall coverings to BS EN 259 offer an extra scrubbable performance as well as defined resistance to impacts. Keep an eye on the debate about cellulose materials and fungi in humid environments and the risk to health.
- Wall or partition structure
This has to be balanced against the additional protecting needed for impact damage that incurs additional costs. These protection costs are justified by reduced repair costs, which can be modelled using “what if” scenarios and risk analysis.
HTM 69 has a matrix showing suitable wall finishes for categories of damage risk. For example, emulsion paint is suitable for light duty whereas for severe duty areas a 2 mm plastic sheet is suitable. Additional protective measures include crashrails and corner protection.
In practice the whole-life costs of a whole wall element, comprising many components, would be modelled for a specific purpose with project-specific cost parameters.