The Costs and Benefits of 1 Inch GI Pipe for Plumbing Projects

If you’re embarking on a plumbing project that requires new piping, one of the first decisions you’ll need to make is what size and material pipes to use. For many homeowners and contractors, 1 inch galvanized iron (GI) pipe is a tried-and-true choice for supplying water throughout a home or building.

What are the costs and benefits associated with 1 inch GI pipe? And how does its pricing compare to other popular piping options like copper or PVC? Below we’ll explore everything you need to know about 1 inch GI pipe price and using it for your next plumbing job.

What is Galvanized Iron (GI) Pipe?

Galvanized iron or steel pipe has been used in plumbing systems for over a century. It gets its name from the zinc coating (galvanization) applied to the exterior of the pipes during manufacturing. This galvanized coating prevents rusting and corrosion, allowing the pipes to last for decades.

GI pipe is available in various diameters, although 1 inch is a commonly used size for home plumbing applications. It connects to other pipes and fixtures using threaded fittings. Galvanized pipe is stiff, strong, and durable, but it does have some drawbacks when compared to modern plastic piping.

The Benefits of Using 1 Inch GI Pipe
There are several reasons why 1 inch galvanized iron pipe remains a staple of many plumbing systems today:

-Durability: The average lifespan of galvanized steel pipe is 40-50 years. The zinc coating provides excellent corrosion resistance, while the iron maintains strength and stiffness. This makes GI pipe well-suited for underground water service lines or interior supply plumbing that needs to stand the test of time.
-Threaded connections: GI pipe uses threaded fittings to connect pipes and fixtures. This allows for easy installation and repairs compared to soldered copper joints or glued plastic fittings. Threaded connections also provide better leak resistance under pressure.

-Strength: Galvanized steel has a high tensile strength that prevents bending or bursting. 1 inch GI pipe can withstand up to 1,000 PSI of pressure from water and steam. This high strength makes it suitable for supply lines, drains, vents, and certain pressure applications.
-Interior coating options: While plain galvanized pipe works for cold water, GI pipe can also be fitted with an epoxy coating that protects against corrosion from hot water and prevents scale buildup inside the pipes. This allows it to handle both hot and cold supply lines.
-Metal material: Galvanized steel is inorganic, so it does not provide nutrients for mold or bacteria growth. This can be beneficial for areas prone to flooding or groundwater contamination.

The Potential Drawbacks of 1 Inch GI Pipe
While galvanized steel has stood the test of time, there are some downsides to consider before choosing it for your next plumbing project:

-Corrosion over time: The zinc coating delays corrosion but does not prevent it entirely. Over decades, galvanized pipes may start to rust from the inside out, leading to leaks, flow restrictions, and water discoloration.
-Not for drinking water: While safe for supply lines, galvanized pipe should not be used for potable water due to the risk of corrosion and accumulation of zinc and lead from the coating. Plastic piping like PEX is a better choice for interior drinking water delivery.

-Rigidity: GI pipe is rigid and inflexible. This can make installations more labor intensive compared to flexible tubing options. The rigidity also means GI pipe is more prone to breaking during earthquakes or ground movement.
-Noisy water flow: Galvanized pipe has a rough interior surface that creates noise and water hammer from turbulent flow. Plastic pipes like PEX have smoother water flow and less pipe noise.

-Threaded connections: While threaded joints are easy to install, they are also prone to loosening over time from vibrations in the system. Plastic or copper fittings use more permanent glued joints.
-Slower, limited repairs: Repairing or replacing galvanized pipe usually requires cutting out and replacing whole sections rather than patching small leaks. Sweat soldering copper is faster for repairs.

Price Per Foot for 1 Inch GI Pipe
For a 100 foot roll of plain 1 inch galvanized steel pipe, pricing averages around $100 to $200, or approximately $1 to $2 per linear foot. This makes it one of the more economical piping materials. It’s also cheaper than similarly sized copper pipe.
However, there are several variables affecting 1 inch GI pipe pricing:

-Schedule: The schedule refers to the pipe wall thickness. Schedule 40 is the standard thickness used for water supply plumbing. But Schedule 80 has thicker walls for higher pressure applications, increasing its price per foot.
-Coating: Uncoated black steel pipe is cheapest. Galvanized coating adds 10-15% to the cost. Epoxy-lined GI pipe can be two to three times more expensive than plain galvanized pipe.

-Straight or coiled: Straight, 20 foot GI pipe sections are easier for installation but cost more. Coiled 100 foot rolls are cheaper but harder to work with.
-Quantity: Buying full rolls lowers the per foot cost compared to buying individual sticks. Larger orders also mean bigger bulk discounts from vendors.

-Fittings: Threaded fittings, joints, elbows and couplings are extra. Couplings range from $2 to $10 each depending on size, material, and finish.
-Delivery fees: Having GI pipe delivered to your worksite adds transportation and logistics fees proportional to order weight.
-Supply and demand: Steel and zinc commodity prices fluctuate over time, driving up pipe costs. Limited supplies also increase prices for contractors.

Comparing GI Pipe to Other Materials
For 1 inch residential supply lines, galvanized steel pipe offers a good balance of strength, durability, and affordability. But depending on your project’s specific needs, it may not always be the optimal choice. Here’s how GI pipe compares to some other popular piping options:

-Copper – More expensive but longer-lasting than GI pipe. Easier repairs and quieter water flow. But copper is prone to pinhole leaks over time.
-CPVC – Much cheaper than copper but more rigid and brittle. Good corrosion resistance for hot water lines. Needs careful thermal expansion provisioning.
-PEX – Flexible, corrosion-proof, quiet water flow. More expensive than GI pipe but faster, easier DIY installations.
-PVC – Inexpensive, flexible plastic piping. Good chemical and corrosion resistance. Not suitable for hot water delivery.

The ideal pipe material comes down to variables like your budget, water type, pipe location, expected longevity, and local plumbing codes. Consulting with professional plumbers in your area is the best way to determine if GI pipe is suitable for your upcoming project.
Key Takeaways About 1 Inch GI Pipe

-Galvanized steel pipe remains a staple of water supply plumbing for its durability, strength, and corrosion resistance.
-Drawbacks include corrosion over decades, noisy water flow, and rigidity during installations.
-1 inch GI pipe costs approximately $1 to $2 per linear foot for standard Schedule 40 plain galvanized pipe.
-Overall plumbing costs depend on pipe coatings, delivery, fittings, quantity, and current market prices.
-Compare GI pipe to copper, CPVC, PEX, and PVC to select the ideal piping material for your specific project situation.

With the right considerations for your unique plumbing project, 1 inch GI pipe can be an economical choice that provides reliable water delivery and longevity. Taking the time to weigh the pros and cons of different piping materials will lead you to a informed, cost-effective decision.