What pipework insulation does
Insulation reduces the rate at which heat moves between the pipe and the surrounding air. On a hot pipe (heating, DHW, steam) that means less wasted heat. On a cold pipe (chilled water, mains cold water) it means the surface stays above dew point, so condensation doesn't form. It also protects against frost on vulnerable runs and keeps surface temperatures safe to touch.
Common materials
Foil-faced mineral wool (Isover, Rockwool) is the go-to for most commercial heating, DHW and chilled services. Phenolic pipe sections (Kingspan) are used where higher thermal performance is needed for less wall thickness. Material selection follows the project specification and the service temperature.
Thickness and specification
Insulation thickness is set by the M&E consultant against BS 5422 or project-specific energy targets. We work to the specified thickness; if a particular run is restricted, we'll flag it and propose a compliant alternative.
Condensation control on cold services
Cold water and chilled water pipework needs a continuous vapour barrier and properly sealed terminations at every fitting. A gap at a bend or a valve is enough to let warm air in and form condensation under the insulation — which then drips, corrodes and degrades.