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

[Ermintrude]

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.

 

[Ch4 plumbing]

Few wraps of ptfe would give a water tight seal.....or a can of crazy foam :2guns:

 

[Best]

Flexi anyone? Ballofix and a 900mm flexi?

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:

 

[PlumbersMate]

What else would you call a street elbow?

 

[jtsplumbing]

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

 

[TBServices]

What else would you call a street elbow?

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.

 

[plumbandplumber]

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?

 

[Best]

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.

 

[Ch4 plumbing]

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.

 

[plumbandplumber]

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?

 

[Ermintrude]

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.

 

[plumbandplumber]

LOL. I make 5" to be 127mm, so your 5" is shorter than mine. Ooh matron!

OK. will use the bender. Real plumber as a last resort.

 

[happyflyer]

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.

 

[galaxy_plumbing]

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.

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

 

[IDCHAPPY]

We buy streets by dozen what u call them male female elbows? Mouth full

I just call them M&F's buddy, my journeyman called them streets 🙂

 

[Ray Stafford]

+ 1 for "streets"

 

[TBServices]

Streets.

 

[jonnyswamp]

M+f's...........dry your eyes mate

 

[plumbandplumber]

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,

Good idea. Example -

Old bedroom rad is 1270mm long, new one will have to be 1300mm long. so, will need a 15mm offset each end, and will also need to add more to the offset because old rad is single panel with no fins -new rad is double panel plus type rad.

So because rad is slightly longer and the tappings for rad valves will also stand further off of wall, will need an offset each end of around 20 to 25mm.

1) Can you achieve such a small offset on a 15mm pipe with benders?

2) With such a small offset needed, should I be pulling 45 deg bends for the offset on bender, or bigger/smaller angles?

Thanks for any help. Benders and practice piece of pipe standing by.

 

[jonnyswamp]

Shouldn't be any problem with those sets, practice on a bit of scrap pipe first. I would try about 30 degrees first,45 may be a bit tight