Flexible gas piping OK for exterior?

Does anyone know if CSST - the corrugated stainless steel flexible gas line - approved for exterior installation? Thank you in advance!

No code gurus around to help Bryan?

Since I know I have stalkers, I’ll post here to see if we can get Bryan some help. Hold on, Bryan. They’ll be here shortly, I think.

Thanks Russel - much appreciated. Also appreciate reading all your posts…


What exactly do you mean by exterior installation?..I know it cannot be buried or touch the ground, but other than being used from Black Iron to say a Barbecue which is fine (appliance connector) I wouldn’t know what you mean by exterior.

I used to install this piping and went to all the certification classes for it when I was a fireplace installer. It cannot be buried. Other than that, you can put it anywhere (with proper strapping). It can run along the bottom of the entire house, out the soffits wherever.


Thanks, Shane.

Preferably in a workman like manner.:smiley: Some people just don’t get it.


Maybe that was done in a workwoman-like manner. :shock: Uh-oh. :roll:

Remove the baffle from the dryer vent, also.

Hi Linda…I may be to late for help but I am certain it is not allowed to go thru walls.
Do not know the exact code off hand but would bet I am right.


Customer owned piping shall be designed and installed in
accordance with the NFGC.

**Corrugated Stainless Steel Tubing

Corrugated Stainless Steel Tubing (CSST) is allowed for new
construction, remodeling, and retrofitting applications in residential
and light commercial structures. CSST shall meet the design and
installation requirements set forth in ANSI/AGA LC 1-1993.
CSST is not designed to be used as a flexible gas appliance
connector and shall not be used as a substitute. The use of CSST
as a final connection for permanently installed appliances, such
as water heaters, furnaces, and boilers is allowed. CSST shall
terminate outside of the appliance jacket where the excessive
heat may ignite or damage the protective coating. The use of
CSST as a final connection of movable gas appliances, such as
ranges and clothes dryers, is not allowed.
CSST shall not be installed outdoors and shall not be run
underground unless installed in a sleeve or conduit.

A Corrugated Stainless Steel Tubing system utilizing a 2-psig or
This is off the Peoples Gas Energy Guide. Chicago’s Gas Company

Am I wrong, or did I see somewhere that there was a class action lawsuit concerning CSST?

Thanks to everyone for their replies/assistance. The GasTite document was very informative and provides the answers I was interested in, at least from the manufacturer specifications. Looks like I will need to check on local requirements as well, since it appears that Chicago does not allow for some of the installation practices approved by the manufacturer (based on the post by Robert Elliott). I am beginning to wonder about this whole concept of being a “generalist” in the home inspection business;-)

Russel - thanks again for the “incentive” post to get the thread started…

My pleasure. My wise ol’ grandmother said, “Learn how to get people to respond.” I have.

What about gas piping that has yellow casing on it? What is it called and is it ok for exterior. (not buried)

That is CSST.

It needs to be at least protected from physical damage Mark.:smiley:

also with this tubing, as you know as well brian, that tape or plumbers putty shouldn’t be used on the flare connector. It’s done commonly and should be watched for when inspecting the water heater and furnace.

This stuff…

101_2707 (Medium) (Small).JPG


5.14 Outdoors [INDENT]When installed outdoors, CSST shall be protected from mechanical damage. A conduit or chase is required for installations in exposed unprotected areas within 6 feet of grade. Conduit shall be supported with proper size pipe hooks, pipe straps, bands, or hangers.[/INDENT] Protective coating must remain intact outdoors. Mechanical joints and associated exposed metal tubing shall be wrapped or protected by shrink sleeves. Appropriate measures must be taken to shield CSST from corrosive environments such as exposure to acid or chloride based cleaning solutions for brick or masonry.
Where passing through an outside wall, CSST shall be protected. CSST must be sleeved where passing though

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