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Spec \"L\" copper

Ken_40 Member Posts: 1,320
Type 'L' for all potable water.

Type 'M' for heating

Type 'K' for A/C and underground potable from curb stop (or well) to inside basement wall.

These are MINIMUMS required by NPSC (New Jersey's plumbing code) and the Mechanical Code(s). One can always use thicker walled tube, but never thinner wall.

As a point of law, if you bid a job that the architect has established the bid spec., and he calls for overkill, you are compelled to use what's specified, as long as it meets (or in this case - exceeds) code - based on law, not code.

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  • Sam G.
    Sam G. Member Posts: 12

    I'm bidding on a pretty big home consruction project (3 mega bathroom, new kitchen, radiant, etc.) The architect has speced "L" copper. We install copper and PEX but in 30 years, I have never seen a spec require "L". The water is not aggressive. any comments?

  • Around here L is for water reguarless; M is for heat; K is for agressive water or compressed air. However I would question, given the price difference whether pex wouldn't be better for th e runs. We still put copper in the rooms but pipe back to the source with pex.
  • Pete_31
    Pete_31 Member Posts: 26

    Any problems that will go through type M will eventually pop through L. I work only commercial and light industrial, M is only allowed on condensate lines usually. L feels better in the scrap bag at the end of the job.
  • Rich Kontny_5
    Rich Kontny_5 Member Posts: 116

    "L" is simply a better grade copper and this is obviously a quality spec'd job. What make boiler is spec'd? What type plumbing fixtures are spec'd? Is copper type "L" spec,
    'd for the domestic water also.

    Believe it or not I worked on a post office project that spec'd brass pipe and fittings. Brass for the water and for all the venting above the "L" spec'd waste side using brass only DWV sweat fittings.

    Just make sure your competition is bidding similar materials. Also make sure you allow for proper labor per jointing methods!

    The general contractor on the post office I mentioned above went bankrupt due to his low bid that ignored the tightly spec'd and inspected project.

    Rich K.

    Make Peace our Passion while supporting our Troops!
  • Sam G.
    Sam G. Member Posts: 12
    this job in northern NJ

    The job is actually an update for the home. The spec was for all piping to be L, waste PVC. Yes the job is upscale.

    You keep saying "around here". where is here?
  • Brad White
    Brad White Member Posts: 2,398
    Type L Copper

    is our default specification for commercial, institutional and high-end residential work. We do not specify type M except for DWV or non-pressure systems (even though it is good for that application). Type K we specify for buried applications and fuel oil as two examples.

    I would bid it as you see it and offer a voluntary deduct alternate to use other materials you deem to be equal in performance. It shows you are thinking about them and the budget but will not jeopardize your bid-to-specifications.

    As stated, at least here in MA, type M cannot be used for potable water systems in plumbing, only types L and K per our plumbing code.

    My $0.02

    "If you do not know the answer, say, "I do not know the answer", and you will be correct!"

    -Ernie White, my Dad
  • JK_3
    JK_3 Member Posts: 240
    in nyc

    IN NYC type l copper is code for domestic water even upto the supply valve to a boiler. another point that i encounter often is that many architects spec what they have been taught or they have a set of materials that they list on each set of plans unless an owner requests something special. usally a call to the architect or owner will clarify for you and you want to make this call because if your competitor priced for a lower price material you will lose the bid. my question is"should i be bidding this job exactly as specd or is meeting local codes and low price what is expected?" hope this helps
    Life is Good !! Enjoy it !!
  • JohnNY
    JohnNY Member Posts: 3,226
    NJ / NYC

    Is the architect an NYC transplant?

    All of NYC uses L tubing for domestic water. My crossover company does work in both states and we often use type L in NJ just because we have lots of it on hand.

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  • nj type l

    i'm in nj and have always used L for water and M for heat and i've only been doing this for 24 or so years ,i do know plenty for guys who use M for water and inspectors never say a thing or don't notice ,big price difference to espically from pex peace and good luck clammy

  • Around here is south western and south central Conn coast. Most old school architects put in that L part in their sleep. I think the copper bid and the pex bid is a good idea. We had a client this summer who wanted no part of pex. She got gov. type L copper. they want what they want.
  • mtfallsmikey
    mtfallsmikey Member Posts: 765
    I've used L

    For probably 15 yrs. or so with everything. Just like the differences between old and new wire, cut out a section of 30 yr. old "M" in good shape, compare to today's "M".
  • Plumdog_2
    Plumdog_2 Member Posts: 873
    codes by state?

    We here in Colo. have many different local jurisdictions, but most of them "adopt" one of the various Codes. Most used Uniform codes until recent years, and many are using I-Codes now. M copper has always been the minimum allowed wieght for Potable, and DWV the minimum wieght for Drainage. I can't imagine why anyone would spec L copper for DWV. How much does a 20 footer of 3" L cost? No wonder the Gubmint is broke if this is what they spec for taxpayer-owned buildings.
  • Ken_40
    Ken_40 Member Posts: 1,320
    As one who sat for and passed the

    Plumbing Inspector's license (but never acted upon this credential) you are correct.

    See above code comments by yours truly.

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  • Shane_2
    Shane_2 Member Posts: 191

    I use type L copper for potable. (or pex)

    Type M for heat (or pex)

    The NSPC(National Standard Plumbing Code), The plumbing code for New Jersey, only requires type M copper. This applies to water service, cold water distribution, and hot water distribution. As per table 3.4, NSPC.
  • Ken_40
    Ken_40 Member Posts: 1,320

    I stand corrected!

    I just looked at my illustrated NSPC and see the table you refer to. I am amazed that 'M' is allowed on potable, but you are right. I am wrong.

    'M' is allowed in NJ for potable.

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  • Shane_2
    Shane_2 Member Posts: 191

    I have seen 3/4 type M copper for water service in 2 1/2 bath homes. I understand trying to make money, but I couldn't sleep at night.
  • Ken_40
    Ken_40 Member Posts: 1,320

    In the pressures seen by potable water tubing, oth 'M' and 'L' will perform equally; how could they not!

    If however, the water is acidic, as in some wells and private systems, BOTH 'M' or 'L' will be eaten and compromised to the point of becoming pin-hole leakers.

    The difference being, 'L' will take a tad longer before becoming swiss cheese. Both however will fail eventually.

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  • Shane_2
    Shane_2 Member Posts: 191

    I mention the 2 1/2 bath home only as an example of a new development which I worked in, not that the number of bathrooms would have any affect on the copper. I personally would not feel comfortable using type M underground or for potable water.
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