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Installing New Rads - Supply Pipes Slightly Different Positions In Concrete Floor

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plumbandplumber

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Hello to all. After a bit of advice about fitting new metric rads in place of old, imperial sized ones. The supply pipes to rad valves in my bungalow come up from concrete floor, so can't move pipe positions.

Some of the new rads are either slightly longer or shorter than old rads and are also slightly different in distance from wall. I need to cut the supply pipes low to floor and install short bits of new pipe with small offsets in them.

Trouble is, because the new bits of pipe with offsets are quite short, the two bends in them for the offsets will be close together. I can't do them in my pipe bender, as when I want to put the second bend in, it's too close to the first bend and fouls the former and guide, etc.

What do plumbers normally do in this situation. Will I be able to do small offsets like this with an internal spring, or won't I get the leverage to bend the pipe?

Any advice welcome, as I'm cacking myself in case I balls this up as the pipes are set in concrete. I have visions of me digging up floors.
 
Get the rad to suit one of the pipes and adjust the other one, also extendable rad valves and m & f endfeed 45 bends are handy for tight offsets
 
You can bend any offset. Over bend first one then put that Bend in former wrong way and bend again.
 
Normally if possible I would have got radiators to suit the pipes. A slightly shorter new rad & then use the longer valve tails would be a lot preferable to a new rad that is a few mm too long when the pipes have no movement. I also try to get similar distance out & use every trick to make it look decent including using the slimmer doubles with one set of fins.
If pipes can't be matched - where you have to use a much larger rad for example, then either use one pipe to valve as stated, or centre the rad on the pipes & bring each pipe to valve using soldered elbows & perhaps a bend out on pipe.
Better to take an hour measuring & figuring out what rad will close match the pipes, than struggling later with the wrong size rad, IMO.
 
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if you are not up to making small bends you could use two street elbows together

edit that should have been one street elbow and one normal elbow otherwise you would need a coupler as well
 
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And do mount the new radiator if possible high up to allow you to use elbows at a reasonable height!
By that I mean, each elbow, street or otherwise, can lose you about an inch or so, therefore 2 elbows will lose you more than 2 inches, so you ideally need the rad up of floor at least 7 or 8 inches perhaps.
 
galaxy_plumbing said:
you could also turn valves a bit so wouldn't have to bend offset
Click to expand...

Lazy, unprofessional looking plumbing, but very true! :smile:

Actually, if the rad valves are the 15mm tail type & heads fitted horizontally, then to angle the valves will not make the heads stick out past the rad, I guess.
 
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Buy smaller radiators and use long valve tails/tail extenders and save altering the pipes.
 
Gun a bit of the floor up to find the original pipes and extend or shorten them, otherwise every time you look at the new rads your going to kick yourself for being lazy.
 
steveb said:
if you are not up to making small bends you could use two street elbows together

edit that should have been one street elbow and one normal elbow otherwise you would need a coupler as well
Click to expand...

Not heard them being called street elbows in years :)
 
We buy streets by dozen what u call them male female elbows? Mouth full
 
All depends on what finish the customer wants and how much they are willing to pay. Dig the pipes ideally but the ways listed above are workable alternatives if the customer doesn't want to pay.
 
The op states it's his own bungalow, nothing wrong with the other options I agree.
 
Someone should have invented a telescopic radiator by now.
 
Installing New Rads - Supply Pipes Slightly Different Positions In Concrete F...

I got a job lot of jubilee clips if you want. 150 a 175mm bands but they will crank down to 15mm I'm sure.
 
Few wraps of ptfe would give a water tight seal.....or a can of crazy foam :2guns:
 
Ermintrude said:
Flexi anyone? Ballofix and a 900mm flexi?
Click to expand...

If you do use a flexi to join up a radiator, then simply turn the rad valves upside down & connect the flexies in a big loop downwards to the pipes. That way you won't kink the flexi & therefore do an unprofessional job.



:smile:
 
Don't know if you are a full time Plumber ! but what you are asking is quite a basic type of a everyday problem, when replacing old size radiators, and easily overcome using the correct fittings
 
PlumbersMate said:
What else would you call a street elbow?
Click to expand...

M&F (male and female)

In this situation, always try to go bigger with the rad, mount it higher if possible to give yourself the most room to work with. Don't forget, your rad valves don't have to be upright, the heads can go horizontal (trvs are designed to be used this way). If you need to angle the pipe it looks better.
 
Firstly, many thanks for all of your replies. Surprised how much help I've had with this one. To clear up any confusion over user name, my now departed father was a plumber. He put this system in, in the early 80s and it still runs really well on the original Concorde WRS boiler. I'm not a plumber, but I did occasionally help him.

So, am I to understand that putting a small offset in a short length of pipe, possibly with an internal spring, would be difficult? I may be able to heat the pipe if this helps? This may be the neatest way for some rads. However, I'm not dead set on this way of piping the rads, as some others have suggested good alternatives. Will have to look at these options and see which may work for each rad to be replaced.

One thing that was mentioned was digging up some of the concrete (screed?) to change the pipes properly. I was assuming that the pipes would be difficult to get to and may be coated in whatever they are set into. But I suppose they may be covered in something for protection. What am I likely to find if I start chiselling up the floor around the pipes? Will the pipes be in a good enough condition/state to allow soldering onto them? Presumably the top layer is screed, how easy is this to excavate - easier than normal concrete?
 
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The screed is normally just a dryish sand & cement mix & is not usually very dense like concrete.
Once you cut a small hole in it, you can enlarge it very easily, even using a club hammer & cold chisel. The screed can be 3 to 6 inch max deep normally.
 
The pipe will possibly have a green tape called Denzo wrapped around it but after all those years it's probably dried up so pull it off and clean the pipe before soldering. + 1 for above (Best) the screed is generally easy to break but just go steady until you know where the pipe is and how deep it is buried.
 
Thanks for your replies Best and ch4.

Another question. A couple of the rads I'm replacing will really need to have an offset in each pipe up from floor to valves. I will cut the existing straight pipes near the floor. Then, because there is limited space between floor and window sill to mount rads, I will have a new piece of pipe to join the cut off pipe near floor up to rad valves of approx 5" in height.

Bearing in mind that a pipe of 5" is quite short, what is the best way of putting an offset in it? Will I manage it with a spring? If this would be difficult, would heating it help?
 
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Thought 5 " was still 125mm? Or is it a short 5" 122mm?

Bend on a 500mm bit of tube then cut down, no use a pipe bender or a real plumber.
 
Why don't you tell us what the centre to centre the pipes are coming out of the floor are and then the centre to centre of the new radiator and then the experts can tell you if it is possible, bearing in mind you may need to fit the new rads slightly higher than the old ones, to take up the offsets, personally I would re-pipe I hate copper pipe in concerete.
 
Best said:
Lazy, unprofessional looking plumbing, but very true! :smile:

Actually, if the rad valves are the 15mm tail type & heads fitted horizontally, then to angle the valves will not make the heads stick out past the rad, I guess.
Click to expand...

i was thinking of having valve on the pipe and have smaller rad so you can bend the pipe a bit to achieve desired offset, haven't done this myself
 
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