THE IRON-CLAD TRUTH:
Solid Reputations Are Cast In Iron.
Your home for the iron-clad truth.
For more than 75 years, the Cast Iron Soil Pipe Institute has been the authority on the use of pipe and fittings in drain, waste and vent applications. We’re not stopping anytime soon. Whether you’re planning, installing or maintaining the plumbing systems in your building, you can trust us to stay ahead of changes in building codes, standards and best practices for installation. For your next project, turn to CISPI. And get more than just the facts.
Get the iron-clad truth.
American-made, universally respected.
The CISPI seal is only found on American-made cast iron soil pipe manufactured to the industry’s highest quality control requirements. The iron-clad truth is that American-made cast iron is the smartest, most efficient, lowest total cost option for most DWV applications.
Trust that’s cast in iron.
The insights and information CISPI brings to the table are built on decades of third-party testing, real-world performance benchmarks and up-to-date code guidance and installation resources. We don’t just promote American-made cast iron because it’s in our name. We advocate for it because the data backs it up. If you want to know what’s best for your project—and your reputation—trust CISPI. Because our mission isn’t to sell, it’s to inform.
Not all soil pipe is created equal.
Performance
Thermal Expansion
per 100° temp change
Cast iron <1”
PVC 3.6”
Crush Loads
Cast iron 8x-10x
more durable
Max Working
Temperature
Cast iron 212° F
PVC 140° F
Hanger Spacing
Cast iron every 10’
PVC every 4’
Life Safety
Combustibility
- American-made cast iron is noncombustible and can be used in return air plenums
- PVC is combustible and does not meet code smoke and flame spread requirements
FIRE RESISTIVE
- Cast iron only requires a noncombustible seal of the annular space between the wall/
floor fire-rated barrier and the pipe - PVC requires complex tested and listed fire rated assemblies and is hard to get right
Sustainability
True legends never die.
Cast iron soil pipe and fittings are made from 96+% post-consumer scrap and are 100% recyclable at the end of life. In other words, they’ll be around longer than any of us will be.
Learn MoreProject Stages
Stage 1
Planning/Design
You can trust CISPI guidance on everything from specification support and code compliance expertise to BIM & CAD resources and lifecycle cost analysis – all geared toward helping you make the smartest design and building choices.
Learn MoreStage 2
Installation/Inspection
CISPI knowledge and resources cover your full range of needs – from best practice installation guides and problem prevention to inspection readiness and on-demand technical support.
Learn MoreStage 3
Operation/Maintenance
CISPI is your go-to resource for everything you need to know about the operation and maintenance of your American-made cast iron systems. We offer reliability data, maintenance tips/
Resources
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CISPI Brochure
All too often, the perceived cost advantages of plastic over cast iron are not what they seem. This brochure will help it all make sense, by comparing six areas that can add cost and complexity: fire resistive construction, crush and deflection underground, thermal expansion/
CISPI Cast Iron Soil Pipe & Fittings Handbook
This newly updated handbook features the latest technical specs, installation guides, manufacturing details, layouts and other useful information for putting cast iron soil pipe and fittings to work for you.
CISPI 301
Standard specification for hubless cast iron soil pipe and fittings for sanitary and storm drain, waste and vent piping applications.