Legislation harmonising European product standards will force manufacturers to upgrade their insulation materials.
The European Construction Products Directive aims to remove barriers to trade by harmonising – and toughening up – product standards for European Union member states.

Construction components that meet the hamonised standard will carry a CE kitemark to show that they that they have been tested against defined product standards. This should help specifiers make informed choices between different types of insulation.

The CE mark for insulation products was to have been introduced on 3 March for all EU countries except Ireland and the UK. This has been delayed, and a meeting will now take place in May to agree a new implementation date. In the UK and Ireland, the introduction of mandatory CE marking will be delayed for at least three years because of problems with fire testing and classification.

However, the British government is insisting that UK companies quote the thermal performance of insulation as defined by the European Construction Products Directive. Suppliers to the UK are free to quote the fire performance of their products if they have CPD fire classification.

Creating product standards for insulation materials is proving a complicated process. The European Commission has found it difficult to harmonise test methods and classification approaches, as these have developed locally according to regional climate, available materials and local preference. The diverse nature of insulation has also made it difficult to compare like with like. As a result some product groups such as foil-faced bubble pack have yet to have agreed thermal standards and won't have to carry CPD thermal performance information when the directive is implemented.

The process is being further complicated by the commission's demand that insulation materials be upgraded to take account of concerns over the environment and insulation materials' reaction to fire. Environmental standards are being forced upwards by a change in the way thermal conductivity is calculated.

Thermal conductivity
To improve thermal performance the directiver is requiring that the thermal conductivity of insulation material be assessed and quoted in a different way. The change means that manufacturers can no longer quote the optimum value of thermal conductivity but must quote a figure based on 90% of their test results.

The effect is to lower the figure for quoted thermal conductivity, which has a knock-on affect on U-values. If specifiers continue to purchase the same insulation after CE-marking comes into affect, there is a danger that their buildings will no longer comply with Part L.

To uphold thermal standards, manufacturers will have to supply either thicker insulation or more efficient insulation products.

Methods being considered to increase thermal efficiency by the various product groups include:

  • mineral wool (low-density products): increase density
  • mineral wool (high-density products): reduce density
  • cellular insulation (non-extruded polystyrene): more efficient blowing agents
  • expanded polystyrene: coating beads with graphite, which manufacturers say boosts thermal performance.

These changes will not only have cost implications for specifiers but may also force them to redesign their construction details to incorporate the new insulation specifications.

Reaction to fire and Euroclasses
Test methods and classifications defining the fire performance of materials have been reviewed under the directive. However, there is a sticking point. In its classification system, the commission now wants fire testing to be carried out "with consideration of the end use" of the product. But as it stands at the moment, CE marking requires only that the product has to be tested "as placed on the market" – that is, tested in isolation.

A problem arises when a product obtains a poor classification when tested in isolation but is intended for use in combination with another material that would give it a good fire rating.

CE marking will only allow the relatively poor single burning item fire rating of the isolated product to be claimed. In future there may be a rating in application and a rating "as placed on the market".

When Euroclasses are introduced for insulation products in the UK and Ireland in around three years, they will run alongside existing national classes for up to five years. In the rest of Europe Euroclasses will be quoted when the directive is implemented and national standards will no longer be quoted.

For more information on Euroclassification, see "Testing times", page 17 in the fire issue of Specifier , published in October 2002.

New British standards relating to roofing

November 2002
BS EN 60335-2-83:2002. Specification for safety of household and similar electrical appliances. Includes standards for heated gullies for roof drainage October 2003
BS 5534 Code of practice for slating and tiling (including shingles). British Standards Institution