Lagging 10mm

[Maxx470]

I cant find anywhere that sell split foam lagging for 10mm heating pipes, would it be any good using the 15mm lagging and cable tieing it tight ?.
Also, these pipes are under my house (wood floors) and some are exposed. Will there be a significant heat loss/£ loss ?.
Some of the pipes are wrapped with hessian looking material and since there is little room to get to the pipes I would prefer lagging that simply slips on.
Any thoughts very welcome.

Thanks

 

[D_Hailsham]

I cant find anywhere that sell split foam lagging for 10mm heating pipes,

It may not be worthwhile insulating 10mm pipes!

This because 10mm is approx the critical diameter. Below this value, the increase in the external surface area of the lagging can offset the reduction in surface temperature so the heat loss is greater than an uninsulated pipe.

 

[Maxx470]

I've done it using 15mm split foam lagging and it's fine.
Surely this is better than nothing ?