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Pipe insulation idea, need advice please.

warnowarno Member Posts: 229
I'm replumbing my boiler system in a combination of copper and pex. I'm wanting to insulate the plumbing once done. I'm thinking about building a box around my runs of pipe and pex then have a spray foamer spray in around the plumbing. I have a solid run of pex about 50 feet long in my crawl space and a run of copper about 20 feet long in the garage that I want to build a 6 X 6 channel around after mounting the piping. Then foam in that channel.

I haven't gotten a quote for the foam yet but I'm thinking this would be cheaper then going with the fiber glass stuff and better then going with the cheap foam wrap stuff. I know there is good foam wrap (armaflex, k flex, ect.) But that stuff is expensive too.

Would this be ok to do for insulating this project?


  • warnowarno Member Posts: 229
    edited April 2016
    The materials for the "channel" are going to be free. We toss out large scraps of lumber and ply wood from building crates for shipping at work. I guess I'm wondering if it would be sort of a "more bag for the buck" situation.

    This is the cheapest I could find the armaflex insulation, which I would probably go with since I have used it before, but I'm thinking the spray foam would be about as much maybe alittle more but would offer a greater R value.

    Should I just not go with the spray foamer or should I at least get a quote and go from there?

    A appreciate the help.
  • SWEISWEI Member Posts: 7,356
    Just remember that spray foam is not 100% closed cell. If it's buried in wet soil, it will eventually get soggy.

    The preinsulated pipe systems use extruded PE or PEX foam, which is effectively immune to moisture ingress.
  • warnowarno Member Posts: 229
    None of these pipes are in the ground or on the ground. The ones in the garage are going to be up near the ceiling level and the ones in the crawl space are going to be mounted to the floor joists. My underground piping is Central Boiler's Thermopex, so I'm not concerned there.
  • SWEISWEI Member Posts: 7,356
    Gotcha. Just wanted to be sure.
  • warnowarno Member Posts: 229
    Could this idea work or should I just go with the normally used items?
  • Firecontrol933Firecontrol933 Member Posts: 73
    A couple of things I would suggest that you keep in mind.
    If you foam in the piping, if it ever needs to be accessed for any reason, you are going to hate yourself. I do hydronics for a living and Murphy is alive and well.
    Another thing to consider is that even if the temperatures that you "expect" to be present in these lines is low enough to cause no damage or deterioration of any foam product...... Murphy is alive and well.

    Build the boxing, line it with foil faced polyisocyanurate insulation and then fill the remainder with fiberglass insulation.

    Just an opinion.
    New England SteamWorksKoan
  • New England SteamWorksNew England SteamWorks Member Posts: 1,397

    If you foam in the piping, if it ever needs to be accessed for any reason, you are going to hate yourself.

    This was my original thought as well. I don't think it's a good idea.

    New England SteamWorks
    Service, Installation, & Restoration of Steam Heating Systems
  • warnowarno Member Posts: 229
    I had had that thought, I guess I just didn't want to think about having to service the piping. I was hoping it would be basically maintenance free. I guess I'll go with the armaflex. Thanks everyone I just wanted to ask the question.
  • rlaggrenrlaggren Member Posts: 159
    One more thought to add to the box concept: The box can be built out of board insulation, cut and glued, provided it is protected. You would then build protection over the insulation, probably using 1x and sheetrock. This may or may not be easier than building a box, then adding insulation.

    Code requires fire protection for most board insulation, depending on what type of building space it's in - generally 1/2 sheetrock will do. In a crawl space, protection from vermin and insects needs to be considered. But that would also apply to almost any pipe insulation.
    disclaimer - I'm a plumber, not a heating pro.
  • GordyGordy Member Posts: 9,530
    Will what's above the crawl space gain any benefit from the residual heat given off by the piping? Is the crawl space vented, or non vented?
  • warnowarno Member Posts: 229
    Dug up the old thread. Lol

    The house this year is on the back burner until next year so I have plenty of time to figure that all out. Now I was looking into the actual pipe insulation though. The split type you just slide over the pipe and glue the seam or use the self adhesive on the wrap.

    The crawl space is vented but I close them in the winter. And any heat lose would hit the living space floor just above.
  • rlaggrenrlaggren Member Posts: 159
    edited October 2016
    > old thread

    Right title, good subject. Stays relevant.

    > split insulation... glue...

    If you go there, figure on using a glue dispenser. A squeeze pump oil can will do the job. Hack saw blades cut the stiff stuff well; not sure about the spongy noodle stuff. An nold hand mitre box makes your corners work better. Some little blocks to keep split sections apart (open) during preliminaries. Take some copper nipples (6") cut nice and square w/a cutter and sharpen all around the pipe on one end. Use to punch out nice holes for pipe branches. 1-1/2" and 2" DWV nipples will give you nice fish-mouths where the branch joins the run. Save the plugs for... plugs when needed.

    disclaimer - I'm a plumber, not a heating pro.
  • warnowarno Member Posts: 229
    Thanks for the advice. I'll put it to good use when the time comes.
  • swvawetheadswvawethead Member Posts: 143
    Being a good boy I searched the forum and found this thread. Got prices from Ferguson for 3/4", 1" and 1-1/4" pipe insulation. Went over there and the counter person went to the warehouse and returned with a box of...polyethylene tubes. I was expecting the black rubber urethane. It's been many years since I bought the urethane pipe insulation. Wanting to insulate exposed pipes downstairs and in the boiler room. Also quite a few feet of non finned pipes in convector runs.

    These days is the far less costly polyethylene tubes ok for any pipes that are not immediately near the boiler?
    Seems to me they can deteriorate but ok in dark locations behind the convector panels.
  • swvawetheadswvawethead Member Posts: 143
    I need to look up the fiberglass insulation mentioned in this thread. I used foil faced fiberglass pipe wrap that came in rolls for the large diameter black iron return pipes in the utility room where the boiler is located. It took time to wind that stuff onto the pipes and was tedious but made a huge difference in the utility room temperature.
  • swvawetheadswvawethead Member Posts: 143
    Hmmm...the fiberglass tubes are nice and maybe good for immediately around the boiler. Costs double of the rubber tubes.
  • jumperjumper Member Posts: 1,568
    Air is a terrific insulator. Arrange for pipes not to contact walls of your chase or conduit and voila. We used to use egg crate cardboard for spacers. I think they were dusted with some fire suppressant.
  • Paul PolletsPaul Pollets Member Posts: 3,360
    I use Imcoa Lok thermacel insulation and the 3/4" wall thickness in exterior walls or crawlspaces. I'd never foam the pipes and know that if you need future access, you're going to be more than sorry.
  • WellnessWellness Member Posts: 108
    edited February 2017
    I have used fiberglass, Armaflex and this pricey, but nicely sealed PVC Reinforced polyester fabric jacketing stuff from BMC. For non -professionals I definitely recommend fiberglass. It's cheap; makes perfect 90 and 45 degree cuts on a chop-saw, can be sealed well with tape and is rated for very high temps. The drawback is that it's paper backing breaks down and becomes easily stained in a wet environments. For irregular pipe runs, Armaflex and other rubber-base pipe insulation are easier to slide over copper pipe.
  • swvawetheadswvawethead Member Posts: 143
    Thank you for your replies and suggestions.

    After being stubborn about using Armaflex or similar rubber tubes I am now considering polyethylene foam tubes at least for some of the pipe sections such as the non-finned runs in the rooms and long ceiling runs in the basement.
    (Paul - Thank you for the "I use Imcoa Lok thermacel insulation and the 3/4" wall thickness in exterior walls or crawlspaces.")

    Durability and insulation wise are they that much less than rubber?
    I don't think I can find any Imcoa branded tubes and not sure if polyethylene tubes in general are similar.

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