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I think this might be my last leak, but it is in a difficult location. Any Help?

I think (hope) I found the last leak, but it is in a difficult place to fix. It is a 3/4 return line that is connected to 3 radiators, one radiator per floor, above that rusted out 90 (going up). That 90 is in crawl space and between floor joists that sit on that concrete shelf (the horizontal part of the pipe is resting on the concrete shelf for a couple of inches before it turns up), so there isn't much working room. It looks like the pipe rising up from the 90 is embedded in the concrete wall, but very close to the surface of the wall, and the wall is about 18" thick.

I could probably chip the concrete away from the pipe about 1 to 2 feet above that 90, cut the pipe there, and redo the rusted out section, but the pipe above the cut is still embedded in concrete and it would be a major job if I had to continue up to the next fitting.

Was it common to embed return pipes in concrete walls in the late 20's?




  • FredFred Posts: 7,874Member
    Any way to abandon that section of pipe and reconnect further back on the horizontal and the vertical before that concrete?
  • JUGHNEJUGHNE Posts: 5,715Member
    If this goes up 3? floors inside the wall, is it conceivable to run a new pipe on the surface of the wall. This is fairly common for both supply and returns.
    What kind of radiators?
  • baj702baj702 Posts: 29Member
    @JUGHNE To run new pipe outside the wall would be a pretty big job. I'd have to disrupt 3 tenants (one on each floor) to replace the whole thing. Cut out the ceilings etc. If that is the only option, then I guess I'd do it, but hopefully there will be something less disruptive...

  • Jamie HallJamie Hall Posts: 10,548Member
    Somehow, when someone says "I've found the last leak" I get worried. Particularly when it is in a pipe which is buried in concrete. Usually iron -- if it is high quality iron -- buried in concrete doesn't rust out that badly. Usually. But where it has already started to go... I'd be concerned that if you took it up a foot or two, you'd get another problem six inches higher up, sometime next winter. And so on.

    I'd rather see the whole riser replaced, though I realise it's a nuisance.

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • EBEBRATT-EdEBEBRATT-Ed Posts: 5,855Member
    I think because the riser connects to three radiators....I would probably think about running a new riser exposed as @JUGHNE mentioned. May not be that difficult and it's a sure thing
  • JUGHNEJUGHNE Posts: 5,715Member
    edited November 2018
    Am I thinking too simple that these rads are all stacked up vertically and the return pipe is also?

    IIWM, I would drill a 1/4" hole in the floor next to the trap. Use a 16" long bit to see where it comes thru the ceiling below. Any tenant I have had over nearly 40 years of owing rental property would understand, most realize that I own the place and not them. Some will bitch and moan but that's life.
    This would show you where you might be able to run a new pipe between each floor. Maybe have to change 2 of the traps to straight flow thru. The piping might come out of the wall and elbow up to thru the floor now.

    All tenants who post here with bad landlord stories would be glad to see some pro-active work done before losing their heat or to get rid of water hammer which most complain about.
    I realize yours are comfy now but when that leak becomes overwhelming to where the boiler rots out and they are out of heat for a fair length of time they might understand your situation (and theirs). FWIW

    You could tell them all that they are getting more "free" heat from the new pipe. ;)
  • FredFred Posts: 7,874Member
    I don't know why everyone thinks it best to replace that return all the way up. The likelihood that the pipe is bad beyond that area that was buried in that concrete, I think is slim. It would seem to me that just replacing it up to the first floor radiator, which must have a Tee there, for that radiator would solve the problem for the next 50 years or so. JMHO
  • JUGHNEJUGHNE Posts: 5,715Member
    Yes, if the concrete was only at the sill plate, but could it be buried in masonry all the way up?
    The only way to tell is cut the wall open at the first floor rad.
    Or just drive a long nail into the wall in several spots to see if it is hollow.
    Could be plaster on masonry wall tile all 8" thick and solid but chiseled open for piping to be installed.

    I can't imagine the pains it would have taken to install steam piping as the wall masonry was laid up. But labor was cheap by comparison. I have seen electrical conduit and iron water piping placed in the concrete walls of rough basements such as mechanical rooms where surface installation would have been simpler and as the time passes more desirable for future maintenance and expansion.

    Can we see a picture of the first floor rad just above this leaker?
  • SeanBeansSeanBeans Posts: 306Member
    I like to use insulation hanger for pilot bits.. they are super thin and easily sharpened with a pair of linesman’s
  • baj702baj702 Posts: 29Member
    @Fred It was even easier. I cut out a section of the the wall about 2 feet above the floor down to the baseboard and about 6 inches wide. The pipes are in a recess in the concrete wall that is about 9 inches wide by 6 inches deep. I cut the pipes (both supply and return) about 1 foot above the floor. I was easily able to get a hand threader on them and then thread on couplings. Then I screwed in an 18" or so nipple with a 90 on it for both to reach back down where the old 90 was. Then connect those 90's back to the supply and return respectively. Done in an hour or so, including repairing the drywall!!!
  • FredFred Posts: 7,874Member
    @baj702 , that is great! It isn't often a job turns out to be easier than anticipated. Well done!
  • Jamie HallJamie Hall Posts: 10,548Member
    Nice work! I think you got lucky.. has to happen once in a while!

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • JUGHNEJUGHNE Posts: 5,715Member
    You had a good day.
    I couldn't get all the tools and material together and out in an hour or so...….I am slow....should retire. :/
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