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Leaking steam lines in earth under concrete in living room

Hi,

I think this is a nightmare i have been dreading for 25 years in this house.

I have at least two steam leaks in my living room in steam supply lines that are under a hardwood floor, laid on concrete. The pipes (supply and return) are buried about 6" in dirt below the concrete. So far two joints have been jack hammered up and both are leaking a lot.   There are lines supplying seven radiators under this concrete am beginning to suspect all the steam lines under this part of the house (no basement or crawl space) need replacing--but that would mean jack hammering trenches through concrete in half my house!

Is there any other answer?  I love steam heat, but it has been suggested by one of the steam guys that i get a Mitsubishi heat pump, and plug off all the steam lines to this part of the house!  Insurance would never pay for that!

Any and all help appreciated!

Comments

  • JStar
    JStar Member Posts: 2,752
    Steam

    A real steam pro would never abandon a system like that. There is always an option. You could even keep some of the pipes exposed, and leave the old ones buried.
  • Jamie Hall
    Jamie Hall Member Posts: 22,947
    Or why lines should never be buried

    directly -- particularly under a slab.  However, folks will do it...



    I would look very closely at exactly where the radiators are.  One would need a floor plan, but it might well be possible to do feed them all from one steam main and return line.  You would have to jack hammer and dig a trench for that one pair of lines, but it might be possible to run it in a remarkably discrete way, but I would have to see a floor plan to figure out how to do it.  Then abandon the leaking lines completely.  If there are other plumbing or electrical lines under that slab, this might be the time to move them into the same utility trench, at least in part.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • SWEI
    SWEI Member Posts: 7,356
    trenchless replacement or relining

    is another option, depending on layout and diameter.  Someone posted a link to a company that does epoxy relining of steam lines a few months back -- don't think we've seen a post-repair report yet.



    Slab on grade construction is fine for garages and industrial space but raised floors make far nicer living.  One more reason I tend to prefer older houses.
  • pipeking
    pipeking Member Posts: 252
    i've seen relining b4,

    but the way it's done i would only think it could be done on big pipe; prolly like 4"-5" and up, i'm guessing. the line i seen it on was 6" and it was a sewer main, and i just don't think it would work on smaller pipe.
  • BobV
    BobV Posts: 5
    -thanks for the help-

    My house was built in 1928, and has basement under 2/3 of the house-- the 1/3 where the leaks are is because the steam supply and return lines were buried under a 10" thick concrete slab in the dirt under it. They are covered with asbestos and wrapped with some type of material on top of that. The cast iron "T" s and elbows are where the leaks are. I have a good steam guy-- and this afternoon he will map out the steam lines-- has some device to attach to the supply and return lines and then the pipes can be traced.

    I may have to take up (destroy) the pegged wide oak flooring in our living room, and the 1 1/2" travertine marble in our foyer to do these repairs, then replace both these floorings with new.

    One suggestion has been to abandon the old lines that go across my living room and trench around the perimeter for new lines to avoid taking up the whole floor.

    The only reason I have looked into the Mitsubishi units for that 1/3 of the house that has the buried steam lines is cost: it would apparently be much less to install the Mitsubishi units.

    Any and all comments appreciated.

    Bob
  • Pumpguy
    Pumpguy Member Posts: 632
    As others have said,

    we need to know how the piping is arranged.  Is it a one pipe or 2 pipe system?  I have seen 2 pipe systems where buried pipes have been abandoned, and steam supply run overhead.  Condensate would flow to a collection receiver with transfer pump and then overhead back to the boiler. 



    Buried steam and condensate lines are best laid in a trench lined with a hydrophobic insulating material.  Hydrophobic materials are non-wetting and prevent moisture contacting the pipe's exterior.  DriTherm  is a brand name of one such product. 
    Dennis Pataki. Former Service Manager and Heating Pump Product Manager for Nash Engineering Company. Phone: 1-888 853 9963
    Website: www.nashjenningspumps.com

    The first step in solving any problem is TO IDENTIFY THE PROBLEM.
  • Jamie Hall
    Jamie Hall Member Posts: 22,947
    Exactly

    what I would suggest --

    " One suggestion has been to abandon the old lines that go across my living room and trench around the perimeter for new lines to avoid taking up the whole floor. "

    And then make sure that the trench was just that -- nicely lined, with the pipes free in it, and a nice removable cover over it.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • BobV
    BobV Posts: 5
    Pumpguy and Jamie Hall

    I have a two pipe steam vapor system.

    built in 1928.

    Hope this helps.

    If you have any other questions that would help you answer my problem, please let me know.

    Bob
This discussion has been closed.