By wadding are you talking about insulation? If they are natural gas pipes it is not necessary. If propane and it gets very cold, it is possible to condense the gas somewhat due to the temperature but doubt it will liquefy. Wouldn't hurt if you use pipe insulation. If you are using butane, primarily found in foreign countries, you can have issues with cold since it can liquefy. Where are you located and what is your fuel source?

GLASGOW Scotland

Are you having problems and what type of fuel are you using?