# Gas Pipe General Questions



## jamiedolan (Sep 2, 2008)

HI;

I am planing out a new run of black iron into my house to replace the old black iron that was installed incorrectly. There will be 1 1-1/4 pipe to replace two 1 inch pipes. I have a couple questions on things I want to verify as I am making the plans.

First, a note that may help others; while several large lumber yards / home improvement stores (where I normally can get all the plumbing stuff from that I need) did not carry anything larger than 1 inch black iron, However, with some searching, I found Home Depot does. Home Depot carries up to 2 inch on the shelf in my local store.

Questions:

Is it correct to run the gas pipe in between the joists or does it need to run below the joists for any reason? (It has to make a crossing in the joists above the heating ducts if I am going to make 1 run instead of 2.)

Second part to this question, if the gas pipe needs to cross above heating ducts, is this ok, does it need to have a certain amount of space between the pipe and the duct, and is there any type of shielding required? (there is currently 1 run that goes above ducts, about 2 inches about, with no shielding that I can readily see.)

I am also making plans as to where the gas line is going to go outside for the grill, and I may put it in a easier to plumb location now if I know I can reroute it outside later. If I want to put the grill somewhere other than near the house later, what are the proper ways to run gas pipe outside (below frost line burial, under a deck that has full footings, etc.)?

One last quick item, what is the proper way to measure for the fittings in your lines? Is there a standard amount of width that a coupler or elbow adds to the length of your pipe?

Thanks very much
Jamie


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## Termite (Apr 13, 2008)

jamiedolan said:


> Questions:
> 
> Is it correct to run the gas pipe in between the joists or does it need to run below the joists for any reason? (It has to make a crossing in the joists above the heating ducts if I am going to make 1 run instead of 2.)
> You can run in between the joists parallel to the span, or through holes in the joists perpindicular to the span. For ease of installation, most people run along the underside of the joists, at least where the pipe must run perpindicular to the joists.
> ...


Jamie, did you check with the local municipality's inspector to make sure they agreed with all the sizing we've done? If not, I really suggest that you do, just in case they have any quirky rules or in case they use an older or different pipe sizing method.


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## jamiedolan (Sep 2, 2008)

thekctermite said:


> Jamie, did you check with the local municipality's inspector to make sure they agreed with all the sizing we've done? If not, I really suggest that you do, just in case they have any quirky rules or in case they use an older or different pipe sizing method.


Thanks for the information, from a phone call I made last week, it sounds like the larger pipe will be fine. I am going to get my plans down accurately on paper for them so I can have the final determination made on the acceptability of my new layout.

I am a good distance from the elec panels for the gas pipe. I do have water that comes very close to my elec panel, I wonder if that is going to be a problem, I should ask that question in the proper thread.

Thank You
Jamie


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## SD515 (Aug 17, 2008)

Is it correct to run the gas pipe in between the joists or does it need to run below the joists for any reason? (It has to make a crossing in the joists above the heating ducts if I am going to make 1 run instead of 2.)
You can run in between the joists parallel to the span, or through holes in the joists perpindicular to the span. For ease of installation, most people run along the underside of the joists, at least where the pipe must run perpindicular to the joists. 

I've never run gaspipe through the joists, not even CSST (corrigated stainless steel tubing...flexible gas line...trade names Pro-Flex, TracPipe, Parker, etc.). Parallel on the joist or under joist when 
perpendicular.

Second part to this question, if the gas pipe needs to cross above heating ducts, is this ok, does it need to have a certain amount of space between the pipe and the duct, and is there any type of shielding required? (there is currently 1 run that goes above ducts, about 2 inches about, with no shielding that I can readily see.)
There's no clearance issues or requirements for HVAC ducts and gaslines. No hazard, no issue. One thing to avoid is the electric panel or subpanel. Gaslines and other plumbing and HVAC cannot run directly above the panels.<<or below

One last quick item, what is the proper way to measure for the fittings in your lines? Is there a standard amount of width that a coupler or elbow adds to the length of your pipe?
Every time I've done it, I wing it. Running under the joists allows you to be an inch or two off in any direction without any real issues. The only critical measurements are the connections to the appliances, and nowadays you can use flexible gas whips for most appliances, which makes things easy. I'm sure there's tricks, but I don't know them! 

I wing it too :laughing: Very few times is it critical to be 'on the money' while installing the main line through the basement. If 2-10 foot pieces coupled together are 20 ft 2 inches...you just adapt a little as you get closer to the final connection.

If you're not going to put in the outdoor grille now, I would run the line in the basement over to the general area where you'll exit for the grille and just cap it off for now.


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## jagans (Oct 21, 2012)

*joists*

I would like to add that should you opt to run perpendicular to the joists by drilling through them drill through the middle third of the joists. The top thhird is in compression, and the bottom third is in tension. You could seriously screw up the load bearing potential of your joists, otherwise. Most people attach to the bottom of the joists for convenience. You can drill perpendicular with a right angle drill but you would have to start outdoors going through the band joist. Probably not worth it to gain an inch or two of headroom. Were I you, I would run Galvanized pipe through the wall to the outside for your grill, and I would core drill a larger than needed hole and spray in foam "Stuff" around the pipe.


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## joecaption (Nov 30, 2011)

Galvanized should never be used for a gas line.


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## rjniles (Feb 5, 2007)

joecaption said:


> Galvanized should never be used for a gas line.


Not a totally true statement, depends on the locality and the composition of the gas.


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## hvac benny (Dec 29, 2009)

joecaption said:


> Galvanized should never be used for a gas line.


We use galvanized pipe for our small residential meter sets in BC.

Btw, this thread is 4 years old.


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## jagans (Oct 21, 2012)

*For the Record, even though its old*

The wives tale that galvanizing flakes off the inside of galvanized pipe was debunked when I was a young man. That was about 45 years ago. Its like I said in another post, some people do not read, and do things just because someone else told them to do it. I cannot tell you how many times I have heard "But I have been doing it that way for 20 years" To which I have often replied. "Yeah, and you have been doing it wrong for 20 years"

Not that black pipe is wrong for gas. The point here is that it does not matter in most cases, except when the pipe will be subject to unusual conditions of corrosion, then I would use Galvy, because black and galvanized are the same type of base material, Mild Steel. The guy who said iron is stronger than steel or steel is more brittle has been hiding in the closet and smoking chesterfields. The advent of steel (Which is Iron with a small amount of carbon added, among other things) is the reason we have skyscrapers, and suspension bridges. Here is what the IRC says according to Dave Oh, IRC is the International Residential Code.

If the building inspector where you live wont let you use it, tell him to take a chance on a tractor. If he wins he can pull his head out of his AXE.

The IRC says:

G2414.4.2 (403.4.2) Steel. Steel and wrought-iron pipe
shall be at least of standard weight (Schedule 40) and shall
comply with one of the following:
1. ASME B 36.10, 10M;
2. ASTM A 53; or
3. ASTM A 106.

The Scope of ASTM A 53:

1. Scope

1.1 This specification covers seamless and welded black and hot-dipped galvanized steel pipe in NPS 1/8 to NPS 26 [DN 6 to DN 650] (Note 1), inclusive, with nominal wall thickness (Note 2) as given in Table X2.2 and X2.3. It shall be permissible to furnish pipe having other dimensions provided that such pipe complies with all other requirements of this specification. Supplementary requirements of an optional nature are provided and shall apply only when specified by the purchaser.

Also see IRC 2415.5. _*The code fully includes galavanized pipe among the piping materials that can be used for both natural gas and LP systems. *_ There is no basis for supposing that natural gas causes the zinc coating to flake off. Obviously, if the specifc conditions in a particular installation create a unique hazard, that needs to be accounted for, but there is no across-the-board prohibition on the use of galvanized pipe for fuel gas applications.


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## ben's plumbing (Oct 6, 2011)

I have but one question.....are you certified to install and service gas piping. this is a topic that rubs me the wrong way....because even the pros need to be certified for this dangerous job and need to have been drug tested ...IT IS NOT A DIY PROJECT...SORRY CALL A CERTIFIED PLUMBER...BEN SR:yes:


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## jagans (Oct 21, 2012)

*Black pipe vs Galvanized*

To add to what I said previously, when I was young, a lot of houses had galvanized piping for their water supply system. This is what was used before copper pipe became widely used for supply. Back then I think black pipe was used for gas because the inside of a gas pipe is not subject to corrosion like a water pipe is, and black was used to differentiate gas from water pipes. There was a time that it was thought that the zinc plating might slough off if galvy was used but very extensive testing proved this to be baseless. I actually read the report a long long time ago, wish I could find it now.

As far as I know, nobody still uses galvanized pipe for water supply any more. Most places use CPVC, or PEX. Some jurisdictions still require copper. Probably those located close to copper mines. :laughing:


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