Everything You Ever Wanted to Know About Lagging

Lagging is simply a way of keeping the water in your pipes, radiators and cylinders warm even when you have turned the heating or hot water off. This will save you money on your gas bills and in doing so will also help the environment. It will be quicker to reheat the water when you need it and will also prevent possible damage from frozen water in pipes.

The best thing is that this is a job anybody can do themselves. Just a few basic tools and equipment and you have an easy weekend job from which you will notice immediate results.


  • Fit lagging to both hot and cold water pipes. You want to be sure that your pipes will not freeze and to keep circulating hot water warm for as long as possible.
  • Foam insulating pipes are available from all DIY stores. They are inexpensive and easy to use. Some will have foil on the inside to reflect the heat, but these are often more expensive.
  • Cut the foam to size and push onto the pipe. It will stay in place but you can secure the edges with tape if required.
  • But the ends together and use a mitre join on corners.
  • Use small cuts in the foam to allow it to go around bends in the pipe work and cut a wedge shape if pipes butt up against each other to form a “T”. This will allow one pipe to sit nicely up against another.

Water Cylinders

  • Measure your cylinder before going to the DIY store to buy a cylinder jacket. These contain mineral fibre insulation and are simply wrapped around the cylinder and secured with string.
  • Make sure the immersion heater cable is outside of the jacket.
  • If you don't want to buy a jacket then simply wrapping the tank with blankets, a duvet or even leftover pieces of insulation will work quite well. But it won't look as neat.


  • Radiators which are on an outside wall can lose as much as 25% of their heat into the wall. Using a reflective backing between the radiator and the wall can improve this.
  • The foil backed polystyrene backings come on rolls which can be cut to size. They are easy to install by simply taping to the back of the radiator, but may be easier to do when the radiator has been removed from the wall.
  • Don't forget that the foil must face the radiator, not the wall.

Simply taking care of these few jobs will pay for itself over the course of a few years in cheaper heating bills. Well insulated and warm homes are also easier to sell as people know they do not have to do these jobs for themselves. Just one more advantage to the simple job of lagging.

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