Raising standards to protect homeowners
Safety alert
Gas boilers - Flues in voids - Advice for Builders and Developers
11 December 2008
Updated June 2009 to include the Gas Safe Register (GSR) which replaced CORGI from 1 April 2009, except in Northern Ireland and the Channel Islands.
The Health and Safety Executive (HSE) has issued a safety alert to raise awareness of the potential dangers from certain types of flues serving gas central heating appliances in some properties. Details of the safety alert have been placed on the HSE website, http://www.hse.gov.uk/gas/domestic/alert021008.htm and has been publicised by them issuing a press statement.
This NHBC briefing note contains important information for builders and developers.
The safety alert relates for the most part to installations where the boiler is mounted on an internal partition wall and the extended flue runs in a void (normally a ceiling void) to discharge externally. This type of installation is most common in multi-storey apartments although any home where the gas boiler is located away from an external wall could be affected. The alert is particularly relevant to installations where the flue runs in a void and provision for access to visually inspect the flue has not been made.
Installations will have been carried out by GSR members or CORGI registered gas installers and in the first instance Builders / Developers should visit the GSR / CORGI websites at www.gassaferegister.co.uk or www.trustcorgi.com to establish what actions they are taking in response to this alert.
The safety alert does not relate to installations where the boiler is mounted on or next to an external wall and the flue goes straight out through the wall, or to installations where the flue rises vertically through the pitched roof void.
Background
You may recall that NHBC have previously highlighted the issue of access to gas flues in voids, initially in Standards Extra 38, dated April 2007, again in Standards Extra 39, dated August 2007 and again in Standards Extra 41, dated May 2008.
CORGI Technical Bulletin 200 (TB 200)* dated June 2007, clarified what was needed to meet the requirements of the Gas Safety (Installation and Use) Regulations 1998 to allow the installer and servicing operatives to be able to check that:
- The flue is continuous throughout its length
- All joints are correctly assembled and are appropriately sealed
- The flue is adequately supported throughout its length.
To achieve this, it is necessary to be able to visually inspect the flue system throughout its route, both prior to initial commissioning of the appliance and subsequently during routine servicing or maintenance of the appliance.
* In England, Wales, Scotland and the Isle of Man, CORGI TB200 was superseded by GSR TB 008 on 1 April 2009. CORGI TB 200 is still effective in Northern Ireland and the Channel Islands.
The following advice explains the builder / developer's obligations under the NHBC warranty cover.
1. Builder / developer obligations - homes not started
Installations must be designed in accordance with the Gas Safety (Installation and Use) Regulations 1998 and GSR TB 008 (CORGI TB 200 in Northern Ireland). Wherever possible gas boilers should be sited on or next to external walls, with the flue going straight through the wall to discharge externally in accordance with relevant Building Regulations and other statutory requirements. Where it is decided to locate the boiler on an internal wall, the flue should be designed / installed by a person or company on the Gas Safe Register strictly in accordance with GSR TB 008 (*CORGI registered gas installer in accordance with TB 200)
2. Builder / developer obligations - homes under construction or completed but not sold
Builder / developer obligations are to ensure that any boilers and flues in properties under construction or completed but not yet sold are correctly designed and installed strictly in accordance with the Gas Safety (Installation and Use) Regulations 1998 and either GSR TB 008 or CORGI TB 200 as appropriate.
3. Builder / developer obligations - homes in the builder / developer's liability period (usually the first two years after completion)
The builder / developer's obligations under the NHBC warranty are to ensure that appropriate remedial work is carried out to put right any breaches of the Gas Safety (Installation and Use) Regulations 1998 and either GSR TB 008 or CORGI TB 200 as appropriate, relating to the original boiler and flue installation reported in their liability period.
Builders / developers should investigate any evidence of a breach of these regulations reported in their liability period. If homeowners contact their builder / developer with general concerns or queries about an installation, the builder should either arrange a check by a GSR member or CORGI registered gas installer as appropriate, or advise the homeowner to do so and notify the builder / developer of any problems identified. (If the property is more than one year old, the homeowner should have arranged for regular checks and servicing to be carried out by a GSR member or CORGI registered gas installer as appropriate, and if this has not been carried out, the homeowner should be advised to arrange this). If the check or service identifies any breaches of the Gas Safety (Installation and Use) Regulations 1998 and either GSR TB 008 or CORGI TB 200 relating to the original boiler and flue installation, the builder / developer would be responsible to rectify these.
4. Builder / developer advice for customers - homes in years 3 to 10 after completion
The NHBC cover in years 3 to 10 includes the cost of putting right any defect relating to the original installation of a flue or chimney, which causes a present or imminent danger to the physical health and safety of anyone normally living in the home.
Builders / developers should advise homeowners with concerns or queries about flues to arrange a check by a GSR member or CORGI registered gas installer as appropriate. If any problems are identified these should be detailed in a formal report to enable the homeowner to discuss the matter further with NHBC Claims. (Telephone 0844 633 1000 and ask for 'Claims'). Any details that builders / developers can provide in respect of installations would be helpful.
This briefing note will be updated as and when further information becomes available.