Chasing radiator pipes into concrete screed floor - correct method?

Participant

Participant

Participant

Caporegime
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Hi all

I'm in the middle of a hall stairs and landing renovation and the next job is to move the radiator from where it was on the right with the exposed white pipes, to the small stud wall where it's hanging in the picture below:

LOi0bM3h.jpeg


This frees up the whole right-hand wall and should look much better. The rad is nearly 7,000 BTUs so easily enough.

The floor is some kind of concrete screed so I'm thinking about using a grinder and an SDS drill to create channels for the pipes.

What is the best method here? Am I best using single runs of plastic rather than copper? What should I fill the channels with after I run the pipe? Does the pipe need to be sleeved or otherwise protected? Clips essential? Any other considerations?

Many thanks.
 
I did similar 4 years ago. The previous owners had buried them half the run and made them come up way early to then be exposed for a long way. So we buried them. I'm far from a professional, but the existing pipes which had been down for a while, were wrapped in tape, and then covered in sand, with concrete over the top. So we did the same.

Touch wood - no leaks since. I think there are basically 2 major important things to consider:
  1. Not letting anything cement based come into contact with copper - it will erode it, and be a PITA to fix the leak.
  2. Account for the expansion and contraction of the copper as it heats up and cools. This will happen a lot in the winter when you have your heating on.
  3. Bonus point, insulation, (I wish I did something about this), you don't want a load of your heat to go into the ground. Your boiler will be working harder as a lot of the heat intended for the radiator dissipates into the floor. Not the end of the world as it should rise into your home.

So I think we covered 1: by it being buried in sand and not in contact with concrete as well as it being wrapped in tape. And 2: by it being buried in sand, it can expand and contract.

P.S. we did the same, used a grinder to make channels, then hammer and bolster and SDS to get the channels out. It was dusty af, so make sure you have good masks.
 
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Would a lesser of two evils be to chase them into the wall, ceiling and back down the newy plasterboard behind the rad.
 
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UPVC trench sections are available with clip on lids or alternatively use a timber above the pipes with filler to the concrete edge
 
Thanks for the thoughts all, no major concerns then which is good.

Mason- said:
I did similar 4 years ago. The previous owners had buried them half the run and made them come up way early to then be exposed for a long way. So we buried them. I'm far from a professional, but the existing pipes which had been down for a while, were wrapped in tape, and then covered in sand, with concrete over the top. So we did the same.

Touch wood - no leaks since. I think there are basically 2 major important things to consider:
  1. Not letting anything cement based come into contact with copper - it will erode it, and be a PITA to fix the leak.
  2. Account for the expansion and contraction of the copper as it heats up and cools. This will happen a lot in the winter when you have your heating on.
  3. Bonus point, insulation, (I wish I did something about this), you don't want a load of your heat to go into the ground. Your boiler will be working harder as a lot of the heat intended for the radiator dissipates into the floor. Not the end of the world as it should rise into your home.

So I think we covered 1: by it being buried in sand and not in contact with concrete as well as it being wrapped in tape. And 2: by it being buried in sand, it can expand and contract.

P.S. we did the same, used a grinder to make channels, then hammer and bolster and SDS to get the channels out. It was dusty af, so make sure you have good masks.
Click to expand...

Thanks for this. Yeah I'm not looking forward to the dust the channel making will produce!

I'm thinking of plastic pipe as I can do single runs then terminate to the radiator in chrome pipe with an accessible (under the flooring)compression elbow.

Maundie said:
When our kitchen was done they put upvc pipe around the copper water and gas pipes to protect them from the cement, would that be an option?
Click to expand...

Definitely if I use copper pipe I'll sleeve it in plastic, but I'm probably going to use plastic and bury it directly.

aVdub said:
Would a lesser of two evils be to chase them into the wall, ceiling and back down the newy plasterboard behind the rad.
Click to expand...

I thought about that and it would also allow the pipes to come out from the wall straight into the rad, which I think is better than coming out of the floor. However I'm not sure it's the lesser of two evils, as it involves destroying a wall and a ceiling and drilling through joists.

Hagar said:
UPVC trench sections are available with clip on lids or alternatively use a timber above the pipes with filler to the concrete edge
Click to expand...

Thanks I'll look into them.
 
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Participant said:
Thanks for the thoughts all, no major concerns then which is good.



Thanks for this. Yeah I'm not looking forward to the dust the channel making will produce!

I'm thinking of plastic pipe as I can do single runs then terminate to the radiator in chrome pipe with an accessible (under the flooring)compression elbow.



Definitely if I use copper pipe I'll sleeve it in plastic, but I'm probably going to use plastic and bury it directly.



I thought about that and it would also allow the pipes to come out from the wall straight into the rad, which I think is better than coming out of the floor. However I'm not sure it's the lesser of two evils, as it involves destroying a wall and a ceiling and drilling through joists.



Thanks I'll look into them.
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The nice thing about plastic is you can do a lot more without any joints. But you presumably would need to elbow up for the rad valves. You have to make sure these are accessible if they are push fit or compression.
 
Mason- said:
The nice thing about plastic is you can do a lot more without any joints. But you presumably would need to elbow up for the rad valves. You have to make sure these are accessible if they are push fit or compression.
Click to expand...

Yes my plan is to leave a little access hole in the screed for the compression elbow (covered by the floor and where nobody will tread) and convert to 15mm chrome pipe out of the elbow.
 
Participant said:
Yes my plan is to leave a little access hole in the screed for the compression elbow (covered by the floor and where nobody will tread) and convert to 15mm chrome pipe out of the elbow.
Click to expand...
Could use a push fit elbow into standard copper and use a chrome rad snap unless you really want chrome pipe? Could also abrade the chrome off where it goes into the fitting back to copper. Not a fan of compression on plastic. Make sure you use a copper olive if you do.
 
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Use a chisel, not a grinder. A grinder will fill the house with dust. If the area is damp (bathroom/kitchen) then the pipes must be protected. Copper in concrete is fine unless there is damp then they will corrode through in no time at all. Often there isn't the space for a retrofitted pipe for insulation, but that's fine. It's perfectly OK to just wrap the pipes in something as long as it's waterproof. Using plastic pipes is a good idea, or, if it's just one radiator, then using plastic wrapped copper pipe.
 
Factor in that plastic pipe has a smaller inner diameter than copper for the same outer diameter pipe due to the plastic inserts.

10mm plastic is more like 8mm copper and 15mm plastic is more like 12mm, this will impact flow rates and therefore the maximum output of the pipe run.
 
Do it all in solvent copper but tape it up similar to below I did for outside tap (i got plumber to do pipework)

Rent a chaser to chase out the channel and use a hoover! Won't be too bad that way.

imgur.com

Outside tap

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I'd use plastic Hep20 pipe. I'm a purist and prefer copper but if it's going in to a floor and inaccessible I'd stick with plastic. If you do opt for copper put a bend in rather than an elbow to help with flow and reduce fittings in the floor and potential for leaks.

I'd avoid a compression fitting in the floor and use an elbow either copper or plastic. Your chase or channel will need to fall toward the radiator if using a plastic elbow or it will protrude out the floor. Then come up in copper and sleeve with a pipe cover if desired.

I'm certain Hep20 pipe can absorb any expansion when warm so there shouldn't be a need to sleeve but technically (or regs) should specify it to be sleeved so it could be removed and replaced if necessary.

Up the wall and through the ceiling is the other option another member suggested, you'll never need to worry about lifting your finished floor if you have a problem.

A wall chaser cuts a nice channel but as suggested it's incredibly messy, even with good extraction.
 
You still want some means to deal with thermal expansion even with plastic, it'll grow both in diameter and length so you want something to decouple it from the concrete. Even just inside a second plastic pipe will be ok but you can't just mortar on top if that was your plan to make good.
 
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