The 1998 concrete flue liners scandal led to a delay of the Part J review. Now it's back, with measures designed to improve the safety of chimneys and heat-producing appliances
In December 1998, Building Homes published an exposé that led to the suspension of the Part J review. The article claimed that a leading manufacturer's concrete flue liner for chimneys could fail in a fire, so construction minister Nick Raynsford ordered an independent risk assessment of flue liners, which delayed the revamp of the heat-producing appliances rules.

The final report from the risk assessor was made available at the end of last year and can be inspected on the DETR website. Work on finalising the revisions has restarted, and the new Approved Document J should be published before the end of summer.

However, although the study into concrete flue liners will lead to changes, the introduction of the new European chimney standards will cause an even more significant shift, particularly in the way chimneys are designated by their level of performance. This will be a big challenge for UK installers, specifiers and users. New European standards for specific chimney products are also close to being published and will replace the British Standards.

A guide is being drafted to explain how the European standards and designation system can be linked to the specific recommendations in the new Part J. This will be published at the same time as the rules.

Although the final draft has yet to be completed, it is almost certain to include:

  • Specific guidance on installing appliances to existing chimneys and fireplaces
  • Recommendations on relining existing chimneys, in response to suggestions from consumer and safety organisations. Chimney relining systems such as double skin, multi-fuel flexible liners and cast insitu concrete linings may be included, provided that they pass the required performance tests.
The revised document could also recommend that, when a gas appliance is replaced that has been used with an existing flexible liner, the liner should be replaced at the same time – unless it is proven to be in good working order.

Many consumer groups and trade bodies have continued to push for mandatory inspection of all heating appliances and flue installations. However, such a system could be difficult to operate. The new Part J is more likely to offer a comprehensive checklist that qualified installers can submit to the relevant building control authority to confirm that the unit complies.

This form of self-certification will be an important step forward in encouraging all installations to be checked for suitability and compliance, and consumers would be well-advised to ask the installer to provide a certificate whenever they have an appliance, chimney or lining fitted. The government is expected to make further moves this year on its proposals for granting "competent persons" the ability to self-certify their work. This will clearly go hand-in-hand with the checklist approach.

There has also been much support for labels on installations that show the type and size of flue, what appliance it can be used with, when it was installed and by whom. The revised document is expected to offer guidance on the details to be included and the positioning.

With changes in appliance design and the popularity of large inglenook-type fireplaces, the revision is also likely to include more detailed advice on flue sizing, the provision of air supply and the positioning of flue outlets.

Although some will object that these changes do not go far enough, the long-awaited revision to Part J will improve safety and it should be welcomed.

Part J: Heat-producing appliances

Part J deals with gas appliances up to 60 kW and oil and solid fuel appliances up to 45 kW. The document is due to be amended this summer to include recommendations on the use of flue liners. The Approved Document provides guidance on:
  • Air supply for combustion
  • Details of flues and chimneys including the location of flue outlets
  • The size and design of flues
  • Suitable materials for flue linings
  • Protection of the building against fire and heat from heating appliances
  • The design of fireplaces and chimneys.