Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Tips on insulating steam pipes

Hi
100 year old home with single pipe steam. Pipes are not insulated in the basement and it can get to be 80 degrees down there. No reason to heat the basement as it’s not a usable space other than laundry. Any tips on how to insulate the pipes?  I see quite a few pipes coming out of the system. Some going up. Some going down, etc. is there anything I should really be aware of that can cause some catastrophic damage by insulating? Are there valves or something I’m supposed to avoid? Thanks for any help. 


Comments

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 13,136
    Use fiberglass pipe insulation with 1" wall thickness. It comes in 3' lengths. It comes pre-split to fit around the pipe. In the old days a special stapler and staples were used to make the split close but that is no longer needed as the new style comes with sticky tape attached. You peal a liner off the tape and stick it together very easy,

    Put all the 3' pieces on first and don't do any cutting till all the 3 footers are on. Then cut your longest cut piece first gradually working toward the shortest for less waste and less joints....save your scraps you will use most of them. They usually give you sticky tape to close the joints between insulation lengths.

    If you choose to by fitting covers, they make covers for elbows (45s & 90s) and tees only out of pvc. You put those on with special white thumb. One trick is to pierce the fitting cover with the thumb tack through one side of the fitting cover first...it makes it easier. You can't buy fitting covers for unions, couplings etc. Tee covers can be used for some valves or in some cases the insulation is "hollowed out" with a knife to make them fit. Cut the insulation with a sharp kitchen knife.

    Most cover steam carrying pipes only and not condensate or return lines. Don't put fitting covers on with tape it looks like crap
  • bburd
    bburd Member Posts: 583
    How well does the system perform? The steam piping above the boiler doesn’t meet trade standards or the manufacturer’s minimum requirements. The header is undersized and the system takeoffs should be before the drop to the equalizer, not after.

    Bburd
  • bombaloo
    bombaloo Member Posts: 10
    bburd said:
    How well does the system perform? The steam piping above the boiler doesn’t meet trade standards or the manufacturer’s minimum requirements. The header is undersized and the system takeoffs should be before the drop to the equalizer, not after.
    Could you explain a little more what you mean in lay terms? The system takes a bit long to start feeling heat in the house. Maybe a good 25-30 mins before you really start feeling the heat. I figured that was due to the heat loss into the basement space. The house has about 14 radiators of different sizes. A few recessed into walls and the rest standard radiators. A larger one and the same room as the thermostat is turned off. Some have old looking Hoffman valves and others have varivalve valves. 

    I am new to the house and the previous owners had been snowbirds for quite some time so I’m not sure how well the system has been operating in winters. I’m located in Westchester county, NY and would be interested in any local people servicing and helping me figure this system out an improving it. There must have been plumbers in an out of the basement for years and I dont know why no one hasn’t suggested insulating the pipes. Is it normal to not have them insulated like that? The oil delivery company does maintenance checks on the boiler but I am sure they are happy with how ineffficent the system probably is. Thank you again for any advice 
  • bburd
    bburd Member Posts: 583
    edited October 2022
    Those pipes were meant to be insulated, even in the era of less expensive fuel. The system will certainly perform better and heat more quickly once they are. @EBEBRATT-Ed gave good advice on this above.

    What I meant by “performance“ was: does the system heat quietly and evenly? The piping arrangement you have above your boiler tends to cause water to be thrown up into the mains along with the steam, which can cause trouble:  water hammer, spitting air vents, uneven heat. If you don’t have these problems, you need not consider correcting the piping.

    What steam pressure are you running? Can you post a photo of your pressuretrol?

    Bburd
  • clammy
    clammy Member Posts: 2,827
    Insulation will help get you get better and more even heat but w that near boiler piping I highly doubt it will help anything except keep your basement cooler . Your main issue as with many w steam is who ever installed saw no value in piping your boiler correctly which in terms means a few things
    1 . High fuel use
    2 terrible distribution
    3 near boiler piping completely wrong enabling boiler to only make wet steam
    That’s the big skinny and the elephant in the room . All the insulation in the world will never correct your issue it’s your near boiler piping . Weather the best steam boiler in the world or the crappiest one is installed it’s the near boiler piping which is the deal breaker ,bad near boiler piping is the most common issue all steam guys see and home owners would rather give you there first born then repipe oddly enough and sad at the same time basically they never see value in it no matter how you explain or word it in writing and even if you show them the installation and operation manual it does not matter plain and simple . . It always seem the original installer is usually always fine and he s always piped in this manor and your the only one w issues .
    Insulating your system piping isn’t a waste but insulating that near boiler piping is a waste it really needs to be re done properly to perform as it should . Steam is very forgiving and will usually perform so so to a point . Many see no value in proper header piping and over sizing headers but how much do they really care about how your system really works or is it just a pay check for the company or the installer ?
    Here’s a few more facts that I ve personally seen as results of bad near boiler piping and time again , which it’s usually takes some time before the rooster comes home to roost . Grooving of the bottom of supply mains due to production of wet steam and and the extra condensate which forms , lack of truely dry steam carrying as many btu as it can as opposed to wet steam which carries hardly any being it’s constantly condensing back to water making for uneven heat higher fuel usage.
    No one likes to pay for anything twice but usually when a boiler is installed and piped incorrectly the price that was paid is directly related to what was done if the installer where to price the job w correctly piping the boiler it would have been surely much more money and possibly he would not have gotten the job . I see this all the time as being told your to expensive and can you lower your price being they see no difference or value in what there being told . When I was young I fought the good fight and I would explain and try to educate , now I let those chose what they want I can only change my small corner of the world and those who see value in doing things right not those who see us as just a commodity and that anyone can do this type of work I personally wish this was true but it is not ,If so there would not be some many poorly piped steam boiler out there and some many unhappy w the operation of there system .
    Do yourself a real favor find some one to repipe your near boiler piping ,flush and clean your boiler ,update main vents and radiator vents if it has not been done in the last 5 years and then insulate your piping . Also check the pitch on all piping and radiators ,flush out any wet returns .if this is never being performed then it s about time or do like most and wait for the poo poo to hit the fan in which case as frank zappa would say the tears began to fall like the writing on the wall
    Peace and good luck ps I tell the truth all the time every time no exceptions
    Clammy
    R.A. Calmbacher L.L.C. HVAC
    NJ Master HVAC Lic.
    Mahwah, NJ
    Specializing in steam and hydronic heating
  • random12345
    random12345 Member Posts: 299
    Non-pro with oil single pipe steam here. Agree with the above. These guys are telling you that you should take a look at your whole system, not just pipe insulation. Could you take a picture of the white sticker on your boiler? Looks like you have a small leak from the tankless coil gasket as well. I believe the venting could be improved by swapping out that tee for an elbow, less resistance.




  • ChrisJ
    ChrisJ Member Posts: 13,887

    Non-pro with oil single pipe steam here. Agree with the above. These guys are telling you that you should take a look at your whole system, not just pipe insulation. Could you take a picture of the white sticker on your boiler? Looks like you have a small leak from the tankless coil gasket as well. I believe the venting could be improved by swapping out that tee for an elbow, less resistance.





    Looks like a Burnham V84 or V85 to me.
    That being the case I'd highly recommend having the cast iron sections closely inspected to make sure they aren't leaking, or going to leak in the near future.

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
    random12345
  • random12345
    random12345 Member Posts: 299
    edited October 2022
    About the pipe insulation...speaking from experience, this is not a fun job. If you can afford to hire someone to do it, that is by far the best option...but it is expensive.

    If you want to attempt to do this yourself, do not buy pipe insulation from the big box stores, it is poor quality.

    In the US, your options are Owens-Corning, Johns Manville, and Knauf. I believe Manson is Canadian and owned by Knauf. I think Knauf is the best option, and is also formaldehyde-free which I like. It is a German company, the other two are US. For the first two, I can recommend https://buyinsulationproductstore.com/, for Knauf you will need to call your local distributors and find the cheapest option.

    Fiberglass pipe insulation is dusty, unless you have a pickup truck or utility van, do not pick up this stuff from the warehouse like I did, spend a little extra to have it delivered. It comes in big cardboard boxes. You will also need to order insulation for the pipe fittings (elbows, tees, unions). Your best option here is Proto or Zeston by Johns Manville. Apparently the same guy started both, Zeston was sold to JM, and then he started Proto. The store above carries both. I ordered 1.5" insulation. I don't recommend it. The installation is too much of a pain. 1" thick gets you 88% reduction in heat loss, 1.5" and 2" gets you only a few percentage points higher. The reason the larger thickness is annoying is because at elbows and tees, anything higher than 1" the two pipe insulation coverings will bump into each other, so you have to take a little off the corner of each.

    You will need an N95 mask and safety goggles at minimum, but I recommend a full face respirator with P95 or P100 filters. It will need to be properly fitted. You also need a Tyvek suit. Fiberglass is not asbestos, but it is a lung and skin irritant. There's no point in being macho about this.

    https://a.co/d/48nFdrt
    https://a.co/d/4qpJXSz
    https://a.co/d/hJACRwL

    You will also need a special knife, like this one:

    https://homedepot.com/p/Milwaukee-6-in-Smooth-Blade-Insulation-Knife-48-22-1921/205935391
  • random12345
    random12345 Member Posts: 299
    Forgot to add, you need thumb tacks as @EBEBRATT-Ed mentioned:

    https://buyinsulationproductstore.com/king-tacks-stainless-pvc-tacks/

    And tape:

    https://buyinsulationproductstore.com/asj-max-25er-roll-25ft-long/

    And last but not least, you need a pipe caliper to measure pipe sizes:

    https://buyinsulationproductstore.com/pipe-caliper-tik-c585/

    That's why I say, if you can get someone to do this for you, that's the way to go...And don't forget about cleaning up the fiberglass dust afterwards either with a certified HEPA vacuum or wet mop so it doesn't get into the rest of your house.
  • ChrisJ
    ChrisJ Member Posts: 13,887
    And here, all I did was buy the insulation, gently wrap it around the pipes and went and took a cold shower.

    I'm not saying it was right, but it's the way I was taught to do it working in construction.
    A cold shower is key..........don't switch to warm or hot water until you're mostly rinsed off.








    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
    PC7060MikeAmann
  • random12345
    random12345 Member Posts: 299
    You could do it that way too, saves money, and might be easier, but I don't know how effective it will be. It needs to be one long continuous sleeve of insulation to trap that heat against the pipe. I see lots of times, people insulating the pipe but not the fittings. The heat is going to escape out the sides of the sleeve. I wonder if anyone has done any studies to measure the difference...Not arguing with you btw...
  • KC_Jones
    KC_Jones Member Posts: 5,354
    I skipped the fittings covers and just mitered mine.  Saves a fair amount of money and just adds a bit of time.  Seal it all up with mastic reinforced with cheese cloth.

    @ChrisJ is correct about the cold water.  I worked in a fiberglass factory and we knew quite a few tricks that being one of them.  Long sleeves help, but one of the best things I used was “Invisible Glove”.  That stuff really helps block the fibers from locking into your skin.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
    PC7060
  • PC7060
    PC7060 Member Posts: 912
    Applying pipe insulation is simple tasks well with reach of most homeowner and is very rewarding. I agree with @KC_Jones, mitering the corners is way to go.  I wad a simple template on cardboard to help with cutting at at something close to 45 degrees.  A serrated bread knife works very well although my lovely wife wasn’t best pleased. 😝

    UL rated duct tape works well to finish up corners.  I also use high temp foam to seal up some of the wider gaps.  Not necessary but I’ve alway got a gun loaded with the stuff so it’s a easy fix for me. 


  • random12345
    random12345 Member Posts: 299
    I think mitering takes more time, and because the pipe fitting sticks out from the pipe, you will need to carve out the inside of the insulation tube to make room for it, so it will be thinner there and won't insulate as well. I believe that's why PVC covers with small fiberglass inserts are made. You do save money though.
  • bombaloo
    bombaloo Member Posts: 10
    bburd said:
    Those pipes were meant to be insulated, even in the era of less expensive fuel. The system will certainly perform better and heat more quickly once they are. @EBEBRATT-Ed gave good advice on this above.

    What I meant by “performance“ was: does the system heat quietly and evenly? The piping arrangement you have above your boiler tends to cause water to be thrown up into the mains along with the steam, which can cause trouble:  water hammer, spitting air vents, uneven heat. If you don’t have these problems, you need not consider correcting the piping.

    What steam pressure are you running? Can you post a photo of your pressuretrol?
    This is the pressuretrol correct?  Also I’m starting to realize that insulation is a DIY project because no plumber or insulator or hvac guy wants to do it. Do any local Hudson valley guys here want to get hired to help?

    in Terms of the performance the system is pretty silent for the most part. Occasionally I hear a bang after the heating cycle. Very rare. Overall it’s very quiet. I’m not sure I mentioned that I just acquired this house so I don’t know how well it performs in winter or how much the oil is going to cost me. I assume a lot.  My personality though is that I need to know how every little thing in my home works and how well and how to fix it if it does not. I’d be even down to “repipe” the near boiler after I see how it performs this sealing as the previous posters have suggested. Not sure what the at entails or how much. Also should someone be maintaining my radiators themselves and making sure all is well. I have no clue how well maintained this system was over the past 20 years. 

  • bburd
    bburd Member Posts: 583
    edited October 2022
    @bombaloo Your pressuretrol appears to be correctly set.

    I suggest you order the book “we got steam heat: a homeowner’s guide to peaceful coexistence”, available from the store on this site.

    If I were you I would insulate those pipes as described above, except for the ones above the boiler because you may end up making changes there in the near future.

    Then live with the system for a while and see how well it works.  If it heats evenly and quietly in general, without water coming out of places where it shouldn’t, then I would not change that near-boiler piping even though it’s not technically correct. “If it ain’t broke, don’t fix it”. It should eventually be insulated.

    Bburd
  • pecmsg
    pecmsg Member Posts: 3,567
    Insulating just the straight pipe will make a huge difference. 
    TonKa
  • bombaloo
    bombaloo Member Posts: 10
    Does anyone in the NY tri-state area want to do this insulation job for me? Honestly I’ve called people and no one does this. 
  • random12345
    random12345 Member Posts: 299
    Handyman, plumber? If they haven't bought this type of insulation before, they may not know where to go. Have you tried pipe insulation distributors? They might know some contractors. For example for Knauf:

    https://knaufnorthamerica.com/en-us/where-to-buy?locationString=220+Henry+St%2C+New+York%2C+NY+10002%2C+USA&latitude=40.71351&longitude=-73.98594&radius=60&requestLimit=20&resultSet=1&totalSets=1&zipCode=10002&dealerType=&accountType=Distributor&products=Pipe+Insulation&metric=false&requestId=LS-01419505

  • pedmec
    pedmec Member Posts: 713
    @KC_Jones Thanks for that tip on the "invisible glove". I do a lot of commercial and we are always opening up insulation and replacing what we rip out. I feel like i want to peel my skin off when i touch that stuff.
  • KC_Jones
    KC_Jones Member Posts: 5,354
    pedmec said:
    @KC_Jones Thanks for that tip on the "invisible glove". I do a lot of commercial and we are always opening up insulation and replacing what we rip out. I feel like i want to peel my skin off when i touch that stuff.
    It wasn’t 100%, but it made things much better.  The forearms were the worst.  We used to also keep tyvek sleeves on hand to cover them for small work.  They were easier and cooler in summer.  We were required to wear long pants and long sleeve Dickies at all times, even in summer.

    The guys in the trim room had full suits with hoods and pressurized air to keep them in positive pressure and the glass out, that is basically 100%.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • PC7060
    PC7060 Member Posts: 912
    I think mitering takes more time, and because the pipe fitting sticks out from the pipe, you will need to carve out the inside of the insulation tube to make room for it, so it will be thinner there and won't insulate as well. I believe that's why PVC covers with small fiberglass inserts are made. You do save money though.
    Good point @random12345, while the mitering works well on the smaller copper lines on my hydronic system, I can imagine it would be more challenging with large iron pipe. 
  • TonKa
    TonKa Member Posts: 68
    edited October 2022
    Put all the 3' pieces on first and don't do any cutting till all the 3 footers are on. Then cut your longest cut piece first gradually working toward the shortest for less waste and less joints....save your scraps you will use most of them.

    I don't agree with this method. IMO, it is simpler to put the 3' pieces on one run, then cut a piece to fit the last part, then use the short piece to start the next run.

    If I'm not mistaken, I think this falls under the category of a 'best fit' vs 'first fit' problem and has actually been studied. Regardless of which way reduces waste, you don't end up playing Tetris with the cut pieces at the end of a long day if you do it my way. :smile:
    bombaloo said:
    Does anyone in the NY tri-state area want to do this insulation job for me? Honestly I’ve called people and no one does this. 

    I believe you are looking for a handyman. Ask your neighbors or the local hardware store for names. I'm sure there's someone nearby who is willing to do odd jobs.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 4,967
    edited October 2022
    Here is a suggestion on the near boiler Re-pipe. but that may not be necessary as long as the system operates comfortably and the little bit of noise is not a problem. If however, you find that the noise is unacceptable, you can try these suggestions.

    Edward Young Retired HVAC Contractor & HYDRONICIAN Services first oil burner at age 16 P/T trainer for EH-CC.org
    MikeAmann
  • There are lots of great videos on YouTube on installing fiberglass insulation.

    https://www.youtube.com/watch?v=qhO9ZRsEcmU
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour
  • bombaloo
    bombaloo Member Posts: 10
    Here is a suggestion on the near boiler Re-pipe. but that may not be necessary as long as the system operates comfortably and the little bit of noise is not a problem. If however, you find that the noise is unacceptable, you can try these suggestions.
    Thank you for that diagram. Other than noise, what other problems would result in having the equalizer before the take offs? And same with the undersized header? 
  • gfrbrookline
    gfrbrookline Member Posts: 723
    Starting with the larger pipes makes the install easier since you will use PVC couplers as you reduce pipe size if you do the install correctly.