Radiator pipework.

[john306]

I'm in the process of swapping years old radiators for new ones.
Upstairs went ok and when I couldn't get exact size radiators I got up floorboards and adjusted pipework.
Downstairs most radiators I can get the correct size except the lounge.
I got the carpet up and found it was concrete.
I need to reduce the pipework by about 8 inches, any way of doing that and how would they have originally fitted the pipework underneath the concrete?
Thanks for any help.

 

[john306]

 

[terryplumb]

Why can't you use a radiator that is closer to the distance between the pipes ? 8 inches seems a lot to have to ammend .

 

[john306]

Hi Terry, 2160 X 700 was old rad, pipe to pipe 2210.
Closest I could find was 2000 hoping I could reduce pipework until I looked under carpet, I should have looked before really.
I know I could fit tail extensions, but would ideally like to reduce pipework so it looks neater.

 

[oldbuffer]

1. The pipework was laid, wrapped in hessian, then the concrete poured.
2. That hessian wasn't waterproof. If the concrete gets damp, its possible it may corrode the copper.
3. The best way to do it would be to dig up all the concrete, then relay new pipes in some form of duct with a solid cover level with the floor. A big job, and you'd have to be very careful not to disturb any damp proof course.
4. If you can't get a radiator to suit, you have two choices:
4a. If the radiator is narrower than the pipework & valves, then:
4ai. Use fixed extenders. (E.g. Screwfix 599HF). Don't be tempted to use telescopic ones, they often leak. OR
4aii. Alter the pipework above ground to put a dogleg in each side. E.g. two 90 degree elbows each side with some short lengths of pipe. Really needs soldering, but can be done with compression elbows.
4b. If the radiator is wider, then again put a dogleg in each side, but running outwards from the radiator rather than inwards. This can be very difficult to do if the difference is very small.
5. Don't be tempted to use braided flexible pipes - they are generally not rated for prolonged use at central heating temperatures, and are restrictive of flow.
6. Have a look at the Myson range of radiators. They still do imperial ones which might fit.
7. Don't forget that whatever you fit may have pipe centres a different distance from the wall, so you might have to alter the pipework anyway.

 

[terryplumb]

What about a longer rad ,you could then bring one pipe close to base of rad ,then take it toward rad end ,then upto the valve. Would be less visible.

 

[john306]

1. The pipework was laid, wrapped in hessian, then the concrete poured.
2. That hessian wasn't waterproof. If the concrete gets damp, its possible it may corrode the copper.
3. The best way to do it would be to dig up all the concrete, then relay new pipes in some form of duct with a solid cover level with the floor. A big job, and you'd have to be very careful not to disturb any damp proof course.
4. If you can't get a radiator to suit, you have two choices:
4a. If the radiator is narrower than the pipework & valves, then:
4ai. Use fixed extenders. (E.g. Screwfix 599HF). Don't be tempted to use telescopic ones, they often leak. OR
4aii. Alter the pipework above ground to put a dogleg in each side. E.g. two 90 degree elbows each side with some short lengths of pipe. Really needs soldering, but can be done with compression elbows.
4b. If the radiator is wider, then again put a dogleg in each side, but running outwards from the radiator rather than inwards. This can be very difficult to do if the difference is very small.
5. Don't be tempted to use braided flexible pipes - they are generally not rated for prolonged use at central heating temperatures, and are restrictive of flow.
6. Have a look at the Myson range of radiators. They still do imperial ones which might fit.
7. Don't forget that whatever you fit may have pipe centres a different distance from the wall, so you might have to alter the pipework anyway.

Thank you.
I thought pipework might have been laid first then concrete poured, but I've taken old radiator off and the pipework moves easily so could easily be in ducting anyway.

I've already got the 2000mm rad here, never even thought of buying bigger.

My only 2 options you make realistically are extenders or dogleg pipework. I'm ok with soldering so will see which option would look better. The saving grace is its hidden away behind settee anyway and can't really be seen.

 

[john306]

What about a longer rad ,you could then bring one pipe close to base of rad ,then take it toward rad end ,then upto the valve. Would be less visible.

Thanks Terry but I've already got it here, I never thought of buying bigger and running pipework under rad. Doh.

 

[denso13]

but I've taken old radiator off and the pipework moves easily so could easily be in ducting anyway.

Or straight through to a void below the concrete.