Loft: Should I lag push fit plastic pipes? Copper ones done.

[KaiConfuzzled]

Hello everyone,

I've been slowly putting right a botched heating install at my cousin's place. One of the last jobs is to lag the pipes. The combi is in the loft, with a lot of exposed pipework, both copper and plastic (speed fit type). The pipes are 15 and 10 mm.

So far I have lagged the cold water feed to the boiler. I've used the foam type lagging.

Firstly, there are a couple of points on this pipe which I could not lag - the push fit joints (copper to push fit) and also the final few inches where the pipe goes into the boiler's underside - the pipe is too close to the wall and other pipes. Should these small sections be lagged? If so, how?

My second question is, should I lag the reamaining pipes? Specifically, its the flow and return CH pipes and the domestic water supply pipes. They are plastic.

I'm considering putting an extra layer of loft insulation down, which will effectively lag the pipes at the same time as they'd be covered. Sorry for the dumb question, but would there be a fire risk? I've noticed that the CH pipes get REALLY hot, so was unsure about having they sandwiched in loft insulation.

Any advice would be greatly received as I cannot find anything in the wiki / faqs or even google.

Many thanks,

KC

 

[oilman]

Lag everything.

 

[Softus]

Firstly, there are a couple of points on this pipe which I could not lag - the push fit joints (copper to push fit) and also the final few inches where the pipe goes into the boiler's underside - the pipe is too close to the wall and other pipes. Should these small sections be lagged? If so, how?

You can use either felt wrap insulation, or the foam stuff of a gauge bigger than the nearby pipework. For example, if you have 15mm pipework into a Speedfit fitting, then use a short section of 22mm Climatube (or whatever) over the fitting, extending a few inches onto the pipework, and cable tied in place.

My second question is, should I lag the reamaining pipes? Specifically, its the flow and return CH pipes and the domestic water supply pipes. They are plastic.

Yes, although not within 1m of the boiler. Lagging the flow and return will keep the heat in, which you want to do, and lag the cold supply to the boiler to stop condensation on the pipe.

 

[Master of None]

My second question is, should I lag the reamaining pipes? Specifically, its the flow and return CH pipes and the domestic water supply pipes. They are plastic.KC

Shouldn't the first couple of meters of F&R be copper not plastic?

 

[Softus]

Shouldn't the first couple of meters of F&R be copper not plastic?

Indeed so, but he hasn't [yet] said that they're not.

 

[Master of None]

Shouldn't the first couple of meters of F&R be copper not plastic?

Indeed so, but he hasn't [yet] said that they're not.

Yep, But he hasn't said they are. Just thought it might be worth confirming.