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A Plumber Told Me

fxrgrunt Member Posts: 157
A plumber was in my house working on something and when he looked at my steam boiler he said I shouldn't have the near boiler piping insulated down to the T because it is a fire hazard. Any truth to this?


  • Jamie Hall
    Jamie Hall Member Posts: 19,427
    Depends on what it's insulated with, of course. Old newspapers? Might be. Fiberglass? No.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • fxrgrunt
    fxrgrunt Member Posts: 157
    @Jamie Hall it's fiberglass
  • mattmia2
    mattmia2 Member Posts: 5,999
    Depends on there the vent is too. Ordinary fiberglass should be considered a combustible material for clearance to the vent. The outer jacket and binder are flammable.
  • jacobsond
    jacobsond Member Posts: 86
    Now what is the temperature of the pipes with steam in them? Pressures your running less than 300. Probably less than 250. Your insulation going to catch fire at 250 degrees? Not very likely. Tell your plumber to just deal with gray water.
    coming to you from warm and sunny ND
  • dopey27177
    dopey27177 Member Posts: 873
    Typically in a home type steam boiler the pressure is set well under five psi. At 5 psi the temperature of the steam is 227 degrees. That temperature is far less than the combustion of paper which is 480 degrees.

    The fiber glass insulation will not burn or melt until the temperatures reach 1000 degrees f.

    Your plumber is some what in the dark about the safety of the use of fiber glass insulation.

    To kinda prove my point, when the boiler is operating and making steam touch the covering near the T that is in question, you will be surprised at how little heat is given off by the covering.

  • fxrgrunt
    fxrgrunt Member Posts: 157
    I figured he was not correct but I wanted to make sure I wasn't just being ignorant.
  • gustielasure
    gustielasure Member Posts: 1
    edited August 26
    Tbh, it's the first I heard such a thought from a plumber. Btw, was his job done well, I hope? Otherwise, you should give us his contact info, as I don't want to contact him accidentally. You know, I moved into another house (Costa Mesa) and I'm looking for a plumbing service nearby. The best option I've found so far is this drain cleaning service https://www.thedraincleaningservice.com/costa-mesa. Actually, a good friend of mine works there. He is a good specialist. Anyway, I'm still open to any new suggestions. I'd be really grateful to you. Waiting for your reply. Thanks in advance. BW