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.

More CSST questions

Timco Member Posts: 3,040
I was told underground MUST be sleeved...a CSST line can be pulled through a 2" or 4" PVC sleeve, and the openings sealed.

Not sure on return duct...sounds like a perfect question for the local inspector as HE has jurisdiction.

Just a guy running some pipes.


  • Tony Shupenko
    Tony Shupenko Member Posts: 54
    More CSST questions

    Lately I've been inspecting building that have CSST. Been to a few seminars on this, but there is nothing like field experience to raise questions.

    Looked at brandy-new construction - some CSST details bother me and I am looking for some opinions:

    1. Can CSST be installed in HVAC return duct plenum formed between joist spaces (see photo)?
    2. Underground CSST to a bar-be-que grill on a masonry patio (see photo)?
    3. Long vertical drops from ceiling to equipment(see photo)?

    Thanks in advance for any comments

    Tony Shupenko

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
    EBEBRATT-Ed Member Posts: 15,344

    Unsupported drops. I think this is an inspectors call. Some inspectors want pipe up to the joists and then ccst. If dropped without ppe it should be secured.
    It can be used underground but the requirements differ by manufacturer. sleeving etc.

    Running through panned ducts. Dosent sound like a good idea.

    So many ccst installations the requirements are slightly different for each manufacturer. The manufacturers instuctions are part of the installation requirements

  • jim lockard
    jim lockard Member Posts: 1,059
    Return Duct

    Runnning gas pipe of any kind thru an air duct, will not fly in the areas where I work. The drop from the ceiling it may be legal but its not the kind of work we want our name attached to. Pipe buried underground best to check the installers guide. J.Lockard
  • Mitch_6
    Mitch_6 Member Posts: 549
    I am not an inspector but

    am a plumber with over 20 years of experience. I have been installing csst for at least 13.

    I am certified in several brands but the basics of all are the same.

    No gas line allowed in duct work.

    Under ground must be sleeved or use pre sleeved version with proper water proofing. We use to have to make the waterproofing ourselves but for a while now they give is a shrink wrap sleeve.

    You can run direct to a non moving appliance but csst must be properly secured, still need stop and union.

    None of that would fly in mass. In doubt contact the rep.

    Mitch S.

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • Tony Shupenko
    Tony Shupenko Member Posts: 54

    Thanks everyone.

    I am going to list these concerns to my client and request that the AHJ re-review (it is always unsettling when I come across apparent and/or known code violations and yet see the "Final Approval" stickers from the AHJ on the window, as was the case here).


    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • Jeff Lawrence_25
    Jeff Lawrence_25 Member Posts: 746


    1) Question 1, 2nd picture. NO!

    2) Question 2, 1st picture. Uh, that would be up to the inspector. I wouldn't allow it, as when the homeowner installs the gas grill, who knows what kind of strain s/he may put on the CSST. (on edit) I realize the CSST is sleeved and I'm adding a comment in addition to the post about it being sealed.

    3) Question 3, 3rd picture. Again, up to the inspector. I agree with another poster that is should be better supported. A question back at you, some of the manufacturers tell that none of the stainless steel should be showing. It looks like the installer cut the yellow covering back too far in any case, but it that the manufacturers approved way?

    Sorry if I'm being a little rough, but I just finished going over an inspection report for a house an extremely good friend of my wife's is buying. It kinda urks me about some of the nit-picky stuff he pointed out and the glaring stuff he missed.
  • Timco
    Timco Member Posts: 3,040
    gas grille termination

    It's not rocket science...
    Just a guy running some pipes.
  • Tony Shupenko
    Tony Shupenko Member Posts: 54

    You are not being rough - I've been doing inspections for 19 years and I am always learning (hence my posts here and on other web sites seeking to seek out the collective knowledge of those in the trenches). As an inspector, I strive to get the glaring and important stuff and some of the nit-pickly stuff (especially on new construction, where clients generally believe that the home should be perfect).

    Anyway, you insight was very helpful.

    Tony Shupenko

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • rucomfy
    rucomfy Member Posts: 43
    Well.....since you brought it up...

    is that a hex bushing in the manual gas shut-off ???? Nice grille but the gas connection is red-tagged.
  • rucomfy
    rucomfy Member Posts: 43

    the humidifier is missing the drain even if it is a 400 series.
  • Robert O'Connor_12
    Robert O'Connor_12 Member Posts: 728
    Tony Shupenko

    Hi Tony,

    #1. No. As per 2003 IFGC Section 404.1 Prohibited locations. Gas piping of any kind cannot be installed in or through a circulating air duct, clothes chute, chimney or gas vent, ventilation duct, dumb-waiter or elevator shaft.

    #2. Depends? Check 2003 IFGC Section 404.1 Prohibited locations. CSST systems must ad-hear to their own protection requirements located within the manufacturer's installation instructions and ANSI LC-1/CSA 6.26 . Also see 404.11 Piping underground beneath buildings Fig. # 404.11 (usually must be sealed inside & within conduit and vented outside. See detail within commentary) In your picture, it would appear the coating has been compromised (coating ripped)Protect Against Physical Damage (IFGC 404.5) That peticular installation, I'd say no (needs work).

    #3.Long drops with CSST are covered under (IFGC 411.1) CSST is included in the list of acceptable means of connecting appliances to the gas piping system. CSST can be directly connected to fixed-in-place nonmoveable appliances in accordance with the CSST manufacturer's installation instructions. Also see Section 403.5.4 & ANSI LC 1/CSA 6.26

    Robert O'Connor/NJ

  • S Ebels
    S Ebels Member Posts: 2,322
    My $.02

    Picture 1: CSST must terminate into a non moveable pipe or appliance or into an approved factory supplied termination fitting. It's not meant to be used as a flexible connector. IIRC, CSST must be sleeved in conduit underground but the conduit cannot penetrate a basement wall without being sealed. This is to prevent gas from flowing into the structure, via the conduit, in the event of a leak. RED TAG

    Picture 2: Here in Michigan steel pipe, with no fittings, may cross a return duct at an angle perpendicular to the duct. That's what I've been told anyhow. It goes against my common sense so I've never done it. Check your local codes. Just a point to ponder.....Nearly every moblie home, house trailer or manufactured house ever made, has the gas pipe stubbed up right into the return cavity surrounding the furnace. I would throw a fit if I saw: A.....the bloody poor job on sealing the sides of those joist headers and, B........the CSST laying against the sharp edge of that header. For cryin' out loud, how many more feet of tube and how much more labot would it have taken to just go around the return panning in the first place. RED TAG in my book

    Picture 3: Most of the inspectors around here demand steel up to the ceiling or joist, supported well and then CSST is connected to that. In cases where a drop like that is made, the very bare minimum would be to support the CSST by clamping it to the plenum with a one hole strap. In addition, I would not accept it due to the proximity of the CSST to the single wall vent pipe. STRIKE THREE! HE'S OOOOOOOUT!
This discussion has been closed.