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Best Source for Pipe Insulation and Fittings Pieces??

AdmiralYoda Member Posts: 627
I'm repiping my boiler this summer and need to re-insulate everything. I installed cheap 1/2" fiberglass insulation years ago but would like to upgrade it a bit, especially the near boiler piping.

First, what is the point of diminishing returns for insulation thickness? 1 inch?, 1.5", 2.0"?

Also, where is a good place to buy the new insulation and the associated fitting pieces and covers?


  • GGross
    GGross Member Posts: 1,045
    If you are near Michigan you could call Acme insulations in GR. I am not sure if they sell to the general public or if you need an account. But I imagine they could help you
  • AdmiralYoda
    AdmiralYoda Member Posts: 627
    @GGross Thank you for the contact, I'm in Massachusetts. Being a homeowner I never have really gone to a local supply house. Not because I choose not to, I just have no idea where they are and buying online is easy and shows up without me having to drive anywhere.

    I was thinking of buying online, but if there is a good local supply house in MA....I'm all ears!
  • jhewings
    jhewings Member Posts: 139
    edited June 2022
    This question has come up several times here. Most of the responses suggest 1" is the sweet spot. I did 1.5" before realizing the above and I'm not unhappy with that choice but there is a jump in price from 1". I bought mine from www.buyinsulationproductstore.com

  • Danny Scully
    Danny Scully Member Posts: 1,424
  • Labenaqui
    Labenaqui Member Posts: 72
    I'm next door in NH. We buy Tubolit 1/2" Thick Split/Self Seal Pipe Insulation @ Home Depot. Half or less Trade Shop Prices & good quality.
    JUGHNE Member Posts: 11,061
    Labenaqui, do you use that on steam system piping?
  • Larry Weingarten
    Larry Weingarten Member Posts: 3,291
    Hi, What do you think of this stuff from Supply House? Says it's good up to 220F. https://www.supplyhouse.com/K-Flex-6RSR100078-7-8-Pipe-O-D-x-1-Wall-Titan-Pipe-Insulation-6 Has anyone used it on steam?

    Yours, Larry
  • pecmsg
    pecmsg Member Posts: 4,845
    Hi, What do you think of this stuff from Supply House? Says it's good up to 220F. https://www.supplyhouse.com/K-Flex-6RSR100078-7-8-Pipe-O-D-x-1-Wall-Titan-Pipe-Insulation-6 Has anyone used it on steam? Yours, Larry
    $32.48 per 6’

    ill stick with fiberglass 
    JUGHNE Member Posts: 11,061
    The 2 online insulation sources listed above had better prices than my independent insulation supplier.

    But when you add the freight into it the total bottom line is a lot higher.

    The independent supplier had a lower freight cost than the others.
  • EzzyT
    EzzyT Member Posts: 1,295
    Buyinsulation.com is Metro Supply in Clifton NJ online sales department. I would go that route since that where I pick up all my insulation products.
    E-Travis Mechanical LLC
    EBEBRATT-Ed Member Posts: 15,519

    The only one I know of is General Insulation. There in Worcester (or maybe Auburn). I don't know if they sell to homeowners, but you could google their # and give them a call
  • pedmec
    pedmec Member Posts: 973
    general insulation is who buy from too and they are also located in Malden, mass. just off of rt 93 coming into Boston
  • Robert_25
    Robert_25 Member Posts: 527
    I bought mine from these guys: https://www.buyinsulationproductstore.com/

    I went with 1" fiberglass and am very happy with it. It noticeably reduced my basement temperature in the heating season.
  • ChrisJ
    ChrisJ Member Posts: 15,671
    I used buyinsulationproducts several times as well.
    Besides 1" being the best bang for the buck there's also the fact 1.5" and 2" get a lot bigger OD and often you'll find you flat out can't fit it in a lot of places.

    A 2" pipe will be 4.375" OD with 1" insulation and 5.375" with 1.5", 6.375" with 2".

    6.375" OD is a big pipe to have in a residential basement or crawl space.

    Here's a scale drawing of a comparison on a 2" steam main

    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
  • PC7060
    PC7060 Member Posts: 1,159
    What @ChrisJ said. I went with 1.5” thick and and it was quite the struggle to make it work in few places. Went with 1” from then on. 
  • Alan (California Radiant) Forbes
    I don't mean to highjack, but I just started using this InsulKnife for insulation and it works much faster than the back saw I've been using for years. Cleaner cuts, too.

    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab