Lagging simply means wrapping your pipes in insulation, this will help delay the start of freezing. It's recommend that you wrap your pipes up ready for winter. Not doing so could cause you to be caught out and have no water on a cold winter's morning or cause damage to your home.
The home-owner called Adams to lag the exposed pipe from the gas califont.
The homeowner noticed that the pipe had been freezing and causing issues with the hot water.
Our plumber / gas fitter called to site that day, They lagged the pipes at the califont to prevent them freezing in the future!
Solve your problems easily.