Sizing insulation for internal 22mm copper heating pipes

[darkart]

I was wondering if anyone knows the correct size of lagging used on copper 22mm and 15mm copper internal heating pipework.

Im having a little argument with a person who says it is ok to use 9mm and I think 19mm should be used?

I have looked on the net but finding information is difficult and was wondering if anyone knows where I can find a regulation, further information or some sort of online calculator?

OOPS! Should have mentioned: Pipes being lagged are directly under a boiler for approx 2 meters in lengh before they disappear into a screed concrete floor.

Many thanks for any response

 

[muggles]

The thicker the better but I think 13mm is the minimum

 

[Steelmasons]

Bet your wife thinks your a bundle of laughs.

 

[AlanE]

Pipes in screeded floor might be more of a problem if they are not protected properly!

 

[D_Hailsham]

Pipes being lagged are directly under a boiler for approx 2 meters in length before they disappear into a screed concrete floor.

If the heat given off by the pipes is 'useful', then there is no need to insulate them.

If insulation is needed, e.g the boiler is in the garage, the thickness required will depend on the thermal conductivity of the insulating material. If it's the typical polyethylene insulation you need:

15mm pipe: - 20mm thick insulation
22mm pipe: - 23mm thick insulation

This will meet the Building Regs heat loss requirements.