Skip to Content

Can CSST Flexible Gas Line Be Used Outside? (Answered)

Corrugated Stainless Steel Tubing (CSST) is a perfect flexible gas line pipe. It is flexible to use under the joist or pavements. If you look at the build quality of this pipeline, you will get why people love to use the CSST gas line.

It’s a famous gas pipe to transfer natural gas. It will last for decades and will give you the optimum service. Let’s find out if you can use it outside.

Can CSST flexible gas line be used outside? 

CSST flexible gas lines can be used outside. The name itself refers to the flexibility that ensures the optimum fittings both inside and outside the home. You will find the CSST gas line in both commercial and industrial areas. If you want, you can use it in your building gas line.

The outside gas line must be compatible and must come with the string build. It needs to bear both the pressure and weather for which the typical gas line is not preferred to use outside. You might use the polycarbonate or plastic-made gas line inside your building.

When it comes to using the gas line outside, it’s your job to ensure safety. You cannot use the regular or any typical gas line. Stainless steel-made gas lines should be your priority. Here, the CSST is also a stainless steel gas line. 

Therefore, you can safely use it outside the home or buildings.

Yellow csst gas line:

You can use the yellow csst gas line outside since it is also a strong gas line that can bear pressure and lightning strike. Usually, the yellow color gas lines are the safest pipe to transfer the natural gas from one place to another. 

They are strong enough to bear the pressure and remain in good shape.

For that reason, you can use the yellow CSST gas line outside and inside your home. You must use this gas line in your house; you can check and confirm this fact. It’s a popular choice, and manufacturers also know it.

Pro flex csst gas line:

You can also use the ProFlex CSST gas line outside the home within a while. 

If you want to install the gas line fast and plan to avoid unnecessary effort, the ProFlex CSST gas line would be greatly relieved. It has a strong and flexible build which will allow you to install it sooner than other pipes. 

Pro flex CSST gas line is a commercially used pipe to transfer the natural gas through the walls, joists, and other ceilings. It has a solid surface to protect the gas line from external damage. Therefore, you can securely use the ProFlex CSST gas line outside.

Can csst gas line be used underground outside?

The CSST gas line can be used underground outside. It is waterproof and can bear high pressure without being damaged or destroyed. If you have options to choose the best CSST gas line, I’d prefer to go for the ProFlex CSST gas line.

It’s best to use any non-metallic gas line to transfer the natural gas through underground routes. You can rely on the quality and will get the best installation process. Using the ProFlex CSST gas line will save both your time and cost in various ways. 

Underground gas lines need to be flexible and must come with non-metallic components. You need to fulfill the requirements to use any gas line underground outside. 

If you use the regular gas line, it will be broken, and you can’t bear the pressure. Consequently, your cost will be higher.

3 reasons why you can use csst gas line outside

You can use the CSST gas line outside because of the firm and flexible build, waterproof features, and ease of installation. I will explain these reasons in detail so that you can understand better. 

Strong & Flexible Build:

The CSST gas lines have the strongest build and flexibility that allow you to use them outside your buildings. Manufacturers use stainless steel and try to give this gas line a perfect design to use everywhere. 

You cannot expect a regular or usual gas line to provide you with the flexibility to use outside.

But the CSST gas line is there to give you everything to use outside your home. Flexibility comes first since you need to install the gas line through walls, ceilings, and underground. 


If you want to use any particular gas line outside or underground, it must have the waterproof feature to avoid any damage or leaks. Outside material must have this feature to resist rainwater and moisture. 

Here, the CSST gas line is a 100% waterproof gas line.

The stainless steel-made gas line will not allow any water or moisture to come inside and damage the gas quality. It will become the safest gas line that you can use outside or underground to supply natural gas.  

Easy to Install:

You can use the CSST gas line outside because it is easy to install. Regular gas lines have some complications in installation. If you use them outside, you need to put in double the effort, which will decrease your productivity. 

So, easy to install should be your first consideration while selecting the best gas line.

Luckily, the CSST flexible gas line comes with the easiest installation process. You can install it on the ceiling, underground and pretty much everywhere.

How long can you run csst gas line outside?

CSST gas lines could be run outside up to mainly 3 feet, but it can be 6 feet for two other types. Generally, the connector can run up to 3 feet. When used for clothes dryers and gas ranges, the limit extends slightly, and the CSST gas line can be run up to 6 feet. 

One concern is that you cannot join or splice the connector with any nipples. The CSST can be run the same both indoors and outdoors. While running the CSST outside, they must carefully use metallic conduct bigger than the pipe to cover it up. 

Any fitting must be avoided when you bury the CSST below your ground level. Be conscious of 3 feet for general and 6 feet for cloth dryer and gas ranges.

How to use csst gas line outside?

Using CSST gas outside requires a careful approach.


The tubing must be supported in an orderly fashion using pipe straps, bands, or hangers proportionate to the tubing’s size and weight. 

The tubing must be routed on top of ceiling joists and other structural parts that conform with the horizontal spacing requirements to be properly supported.


Any exposed portions of the stainless steel tubing must have tape or a sleeve wrapped around them to protect them from potential hazards posed by cleaning masonry solutions based on chlorine or acids. 

Due to its long-lasting nature, self-bonding silicone tape is the material of choice here.


When installing Gastite via a sheet metal enclosure (such as a fireplace), make sure the tubing is routed or supported so that it does not come into contact with the enclosure itself. Rubber grommets can be utilized if direct contact is unavoidable.

Where can I use CSST gas line?

You can use the CSST gas line everywhere. Let’s see what the best places for using this gas line are.


For underground usage, it must be protected from corrosion by being installed inside a sealed conduit. A protective sleeve sealed against the foundation will be wrapped around any piping that must pass through the foundation wall. 

It has to be encased in a non-metallic conduit half an inch larger than the pipe itself. The underground segment must be devoid of any fittings.

Interior Walls:

One of the many advantages CSST comes up with is its flexibility. You can use it anywhere you want. Your interior walls are no exception. It is highly durable, so you should have it in your internal walls without any worries. 

Gas piping systems that use CSST have fewer joints, and as a result, they have a lower risk of developing leaks.


Use of CSST in the outer environment is acceptable. UV protection and flame resistance are both included in the jack. 

For this, an external pipe installed above ground must have a stable support system and be placed in an area where it will be safe from being damaged by the elements. 

Pipes that go through outside walls must have an additional layer of protection against corrosion in the form of a coating or wrapping made of an inert material that is certified for use in such situations.

Final Thoughts

Because of the easy installation, waterproof & durable build quality, you can use the CSST flexible gas line outside. It’s a perfect gas line to use both inside and outside the building. You can use it in commercial and industrial areas since it has the best build quality and durability.