10mm heating plastic pipe lagging

[darkart]

When installing 10 mm plastic Polyfit pipework under floors to radiators on a new combi system, should the 10 mm pipe be insulated? If so, is it a manufacturer's requirement or building regulations?

Many thanks in advance.

 

[Swwils]

4.24 In a new system, all of the following new pipework should be insulated.

a. Primary circulation pipes for heating circuits where they pass outside the heated living space, including where pipework passes into voids.

b. All primary circulation pipes for domestic hot water.

c. All pipes that are connected to hot water storage vessels, for at least 1m from the point at which they connect to the vessel.

d. All secondary circulation pipework.

4.25 In an existing system, when a boiler or hot water storage vessel is replaced, any accessible pipes in the dwelling should be insulated

 

[darkart]

4.24 In a new system, all of the following new pipework should be insulated.

a. Primary circulation pipes for heating circuits where they pass outside the heated living space, including where pipework passes into voids.

b. All primary circulation pipes for domestic hot water.

c. All pipes that are connected to hot water storage vessels, for at least 1m from the point at which they connect to the vessel.

d. All secondary circulation pipework.

4.25 In an existing system, when a boiler or hot water storage vessel is replaced, any accessible pipes in the dwelling should be insulated

Much appreciated many thanks, which document is this from please?

 

[Swwils]

Part L