Hot/cold feeds in insulated raft

[JackofAll]

Can someone explain to me where the hot and cold feed are run in on an insulated raft, thanks.

[Carrerahill]

Generally I would say avoid it, however, if you need to, put in a services channel with a lip formed that you can then put a ply cover on. Alternatively, lay ducts with popups through the slab on big radiused bends. 

[JohnMo]

I put the cold below the insulation and used a plumbing manifold in a central point. Used Pert-Al- Pert pipes in conduit,so the can be removed as per building regs.

 

Didn't do hot in floor, but would do that within the insulation, as above.

[JackofAll]

28 minutes ago, Carrerahill said:

Generally I would say avoid it, however, if you need to, put in a services channel with a lip formed that you can then put a ply cover on. Alternatively, lay ducts with popups through the slab on big radiused bends. 

Avoid what, the services channel seems like a good idea

[JackofAll]

This is what I thought the lay out would be like, 1 cold feed from pumphouse in a 4inch wavin pipe coming up in kitchen under sink then duct to plantroom from kitchen(run hot back through same duct)(do i nned a seperate feet from pumphouse direct to cylinder in plantroom), duct from plant room to 2 bathrooms which happen to be side by side containing hot and cold. If I was to use services channel as previously stated could I just t off for each station(toilet, sink, shower etc?)

[Roundtuit]

I'm no plumber, but I think your rising main is best coming up into the plant room, then run everything else internally in the ceiling, dropping down the wall to sinks etc as required.

[JackofAll]

1 minute ago, Roundtuit said:

I'm no plumber, but I think your rising main is best coming up into the plant room, then run everything else internally in the ceiling, dropping down the wall to sinks etc as required.

You could well be right, though wouldn't that be alot of wall chasing and on a 4inch block wall with pipe insulation fitted I would imagine the chases would need to be deep?

[JackofAll]

56 minutes ago, JohnMo said:

I put the cold below the insulation and used a plumbing manifold in a central point. Used Pert-Al- Pert pipes in conduit,so the can be removed as per building regs.

 

Didn't do hot in floor, but would do that within the insulation, as above.

Where did your pipes run from manifold John, in floor or through ceiling?

[JohnMo]

Cold ran down from Manifold, under the floor, then up at the point where the sink was going to be.

 

Photos of stop cock and cold manifold. Plant room is in an upstairs loft section, so main water goes there also.

 

Other photo you can see various white pipes coming up at the outside walls.

 

Hot pipes are in the ceiling and drop down.  Walls were all battened to form service gap the plasterboarded 

[Nick Laslett]

I just ran ducts for the hot water pipes in the raft. 
 

This was standard 50mm twin walled ducting. 
 

https://www.builderdepot.co.uk/cable-ducting-twin-wall-black-per-metre-50mm

 

The ducts ran under the rebar mesh. The plastic mesh supports were 50mm high.