Advice on frozen pipes

Date issued: 11th January 2010

Advice to householders, business, schools, and managers of buildings

Owing to the prolonged cold snap, resulting in frost penetrating deep into the ground, many householders, businesses, schools and community buildings are experiencing problems due to frozen water pipes.
The two most common sources of the problem are:

• A service pipe between the water main and the building, which because of the inadequate depth at which it has been laid has been frozen; or
• A pipe in an attic, which because of inadequate lagging has frozen

Because of the diverse nature of individual cases it is not feasible to issue “one size fits all” advice.   Pipes which are frozen underground are virtually impossible to locate and even then would require ground excavation to access the frozen section in order to thaw it out- an extremely difficult and expensive task. In general, householders and others experiencing problems with frozen pipes are advised to contact their own plumber. The plumber should be able to locate the frozen blockage, and may be able to advise on ways of thawing or bypassing the frozen pipe in the short term.

Individual tips which might help to avoid frozen pipes are:

• If you have an outside tap, ensure properly lagged or wrap a towel around it in interim.
• Leave an electric light on in the attic adjacent the cold water tank ( not an energy efficient bulb)
• Open the attic door to allow heat into the attic
• Ensure that there is a gap in your attic insulation immediately under the storage tank – attic insulation should be laid above and around the storage tank, not under it
• Leave heating on for longer than normal.
• Place a piece of insulation – e.g. carpet or matting – into the stop cock box if accessible to you or even over your external stopcock.
• Farmers and landowners should carry out regular checks on service pipes to water troughs
• For buildings vacant over a period of time, ensure heating system set to come on via timer, over a number of times per day.
• If you own or manage a building which is vacant or has been unused for a period – e.g. a school over the Christmas holidays, or a holiday home – please open it up and check for frozen and leaking pipes

When carrying out any measures to avoid pipes freezing, please ensure that these measures are carried out in a manner which is safe and does not create a hazard for you or for the general public.

Advice on heating systems for those with no water supply.

In most cases you can continue to operate your heating system even with no cold water supply coming in. In most instances there are two tanks in your attic, the bigger one to supply the bathroom, toilets and hot water cylinder, and the smaller one to serve the heating system. It is very important to ensure that the smaller tank remains full and that the pipes in and out of it are not frozen.
Some systems use a pressure vessel (usually either orange or white) instead of the small tank in the attic. If your heating system uses a pressure vessel, you should contact a properly qualified plumber or heating contractor for advice, as there are various types of vessel and they are generally sealed.

Advice for when a thaw sets in

In the longer term, when the thaw sets in, some of the frozen pipes will have burst and will need to be repaired. With this in mind, it is very important that householders and others should now familiarise themselves with the location of their stopcock, ensure that there is access to the stopcock, and know how to turn off the water supply to the house or other premises. Early action to turn off the water will reduce the potential for damage, particularly from burst pipes in the attic.