Lagging CH pipes

[John]

I have a load of 28/22mm pipe that comes out of the boiler & disappears in various directions around the house to the cast irons rads. Most of these go under suspended (timber) floors and vertically occasionally to the next floor. Some of the pipes are lagged, most are not. Is it worth buying a load of lagging to insulate the rest? Am I likely to recoup the cost of the lagging against the efficiency increase by not heating unnecesssary voids etc between floors ? I ask this because there are other flats below/above in certain rooms and I would rather not let them enjoy free heating where possible.

John

[Andrew Gabriel]

Well, there's very little point insulating pipework where the lost heat goes into your rooms anyway. I insulated the pipework under a suspended ground floor, and where it ran through a cupboard where I might want to run a PC sometime, but where they're routed between upstairs floor and downstairs ceilings, I only insulated them where there's a bunch of electricity cables passing nearby.