Opinion on thoughts for solving pipe problem

[Alf1999]

I am currently trying to solve a problem in terms of laying pipes in a screed floor. The old copper pipework under the screed is leaking and so I am going to abandon it and lay new pipe. I can't box them in or run from the ceiling. So my solution, after some research, was to bring in a new flow and return run from the outside boiler at the back of the house, run these pipes under the kitchen units into the cupboard under the stairs, connect these to a manifold (standard plastic hep20 3 port manifold) , and run plastic pipe in conduit to each radiator individually in their own channels, with no joins under the screed. I have dug out the channels in the screed and bought the pipe to do this myself, but just before I go and actually finish it off I am wondering is this definitely a sensible thing to do? I didn't see any other option as boxing in would mean crossing doorways, and I couldn't drop down from ceiling. Also I'm wondering how to do the radiator tails so they don't look bad as bendy plastic pipe coming out of the floor isn't going to be ideal. I will get a plumber to come and connect the pipes to the boiler when finished.

 

[ShaunCorbs]

Only option is to have a joint / elbow in the floor and come out in copper straight into the rad

 

[steadyon]

1. As ShaunCorbs, elbow in floor and copper to the radiator valves. It would be worth putting the joint in a cavity within the screed, with a cover to the cavity with its top surface level with the floor. Allow additional room within the cavity and the approach to it, so that there is some flexibility to move the pipe to and away from the wall should you ever change radiators.
2. Don't forget you need to use barrier pipe to avoid oxygen penetration.

 

[cjg]

use barrier pipe to avoid oxygen penetration.

as above

 

[Alf1999]

Only option is to have a joint / elbow in the floor and come out in copper straight into the rad

1. As ShaunCorbs, elbow in floor and copper to the radiator valves. It would be worth putting the joint in a cavity within the screed, with a cover to the cavity with its top surface level with the floor. Allow additional room within the cavity and the approach to it, so that there is some flexibility to move the pipe to and away from the wall should you ever change radiators.
2. Don't forget you need to use barrier pipe to avoid oxygen penetration.

Is there no way to have a join above floor or bring the pipe up straight (in a 90 degree rigid conduit or something?) and cover it/ sleeve it in something? I’ve seen metal pipe sleeves in chrome for covering copper pipes, and was wondering if they could be used for plastic pipe as well? Seems like it might be a bit fiddly and the pipe will want to fight the sleeve/cover but would it do the job or is an elbow my only option?
I have made sure to use barrier pipe and everything is hep20 to keep it all the same brand and fittings

 

[ShaunCorbs]

Yep cover won’t hold the pipe straight enough also you will need a deep chase at the end due to the bend radius of around 4”

 

[Alf1999]

Yep cover won’t hold the pipe straight enough also you will need a deep chase at the end due to the bend radius of around 4”

Ok I’ll use an elbow just placed at floor level, so noticing a leak will happen sooner and be less disruptive to fix in the case it happens.
What elbows are the most bullet proof for this sort of thing? Compression, push fit, what brand is best....
Many thanks for your advice so far, it’s made me feel a lot less uneasy about the situation

 

[steadyon]

Although I'm not a fan of plastic piping, I'd say you are less likely to have trouble with a push fit elbow than a compression one.

 

[ShaunCorbs]

Push fit also one with a non removable collar eg speedfit or hep (white)