How deeply are plastic central heating pipes usually under screed

[nick83]

Despite powerflush new lockshields,and trv's still one rad not heating.I took it off and checked flow and return.Good from return but just a drip from flow end.I feel it is blocked underfloor plastic pipe.Just wondered how deep they are usually laid.-house approx 20yrs old
appreciate any rough idea.Obviously i have no clue where all these pipes go either.

 

[SimonG]

Is the plastic grey in colour?

 

[nick83]

Is the plastic grey in colour?

You will find this unbelievable ,but I don't know.All the pipes are hidden under floors etc and the boiler and airing cupboard are all copper.Also the tails that stick out the floor are copper.I was told they are plastic when I moved there.Also when a rad comes off you can 'swivel' the copper pipe 360 degress as if pushed into a fitting.

 

[Riley]

You’ll need to check. It could be that it’s not barrier pipe and is blocked solid

 

[nick83]

You’ll need to check. It could be that it’s not barrier pipe and is blocked solid

thanks for that.I can chisel a bit away from around the base.They have some foam cladding stuff where they enter the floor.
What is barrier pipe exactly?All upstairs has always been fine.May be best to bite the bullet and repipe downstairs

 

[Riley]

Barrier pipe is plastic pipe with an inner metal layer preventing air ingress into the system

 

[Pickwickpick]

Non barrier pipe is permeable to oxygen with all the associated corrosions/magnetite/blockage issues

 

[nick83]

Barrier pipe is plastic pipe with an inner metal layer preventing air ingress into the system

thanks for the information.Soundslike 18yrs ago in a newbuild probably not barrier pipe

 

[Riley]

Have to have a look