Water Regulations and Pipe Lagging

Just bought pipe lagging from B&Q/Wickes for the exposed pipework in the loft (my builder's plumbers didnt lag any of the pipes...) Most of the pipework is 22mm pipe, also some 15mm pipe.

1. Can anyone advise how thick lagging needs to be? I bought it in 2 thicknesses - 13mm and 19mm - because some of the pipework is quite close together and there isnt much room to maneouver (See picture


The 19mm one says it is Water Regs compliant but the 13mm one doesn't. Is it still okay to use - if I just cant fit the 19mm one?

2. For areas where I cannot use any lagging (the pipes are almost touching!) what should I use? I have had a look at reflective foil or Wickes do a roll of felt pipe sleeving....

3. Do I need to lag the Discharge pipes too? If they're meant for boiling water surely its unlikely they'd freeze?

Many thanks as usual

I would get the builder back, that is a shocking standard of work.

Is he qualified to install unvented cylinders?

Gasman77 said:

I would get the builder back, that is a shocking standard of work.

Is he qualified to install unvented cylinders?

Click to expand...

He is not, nor is his plumber. Thats why the Benchmark booklet was left completely empty. But all this has already been dealt with in depth in another of my posts //www.diynot.com/forums/viewtopic.php?t=247526&highlight= .
I have since had a GS-reg fellow with the unvented ticket come and put right the pipework where possible - however he did not feel that ripping all the pipes out and relaying them properly would be worth it for me, so did what he could. Hence the fact those pipes look like that...hence my post re the lagging....

(If you're interested, here's some pics of the rectified pipework: