When it comes to selecting the right pipe for your culvert, many people may quickly decide based on the initial cost. Corrugated metal pipe (CMP) often appears to be the more cost-effective solution. However, when considering the long-term value, heavy wall steel pipe stands out as the better investment. In this blog post, we'll compare the advantages of heavy wall steel pipe versus corrugated metal pipe and demonstrate why the former is the superior choice for your culvert needs.
Initial Cost Comparison
Let's start by comparing the costs of installing both types of pipes.
Corrugated Metal Pipe (CMP):
Cost per foot: $30
Total cost for 24" diameter x 40' pipe: $1,200
Installation cost: $600
Road pack: $200
Estimated total cost: $2,000
Heavy Wall Steel Pipe:
Cost per foot: $70
Total cost for 24" diameter x .375" wall x 40' pipe: $2,800
Installation cost: $600
Road pack: $200
Estimated total cost: $3,600
While CMP costs significantly less upfront, this is only part of the story.
Thickness Comparison
Another crucial factor to consider is the thickness of the pipes.
Corrugated Metal Pipe (CMP):
Typical thickness: 16 gauge (approximately 0.06 inches)
CMP relies on its corrugated structure for strength, which can be susceptible to damage and wear over time.
Heavy Wall Steel Pipe:
Thickness: 0.375 inches (approximately 6 times thicker than 16 gauge CMP)
The substantial thickness of heavy wall steel pipe provides superior durability and resistance to damage, ensuring a longer lifespan.
To put this in perspective, imagine a sheet of paper (about 0.004 inches thick) versus a thick cardboard piece (about 0.024 inches thick). The difference in strength and durability is considerable, similar to the difference between CMP and heavy wall steel pipe.
Lifespan and Maintenance
One of the key differences between these two types of pipes is their lifespan.
Corrugated Metal Pipe (CMP):
Life expectancy: 15-20 years
CMP is prone to trapping debris, which can slow water flow and accelerate wear and tear.
Coatings: CMP can be aluminized or galvanized to extend its lifespan, but these coatings eventually wear off, especially in harsh environments.
Heavy Wall Steel Pipe:
Life expectancy: Up to 70 years, depending on factors such as soil acidity, traffic, general maintenance, and water flow.
Smooth walls allow for uninterrupted water flow and prevent debris buildup, reducing the need for frequent maintenance.
Long-Term Cost Analysis
To truly understand the cost-effectiveness, let's calculate the total cost over 70 years, factoring in potential increases in steel prices due to inflation. Over the past four years, we have seen steel prices nearly double. Let's conservatively estimate a 2% annual inflation rate for steel prices over the next 70 years.
Corrugated Metal Pipe (CMP) Replacement Costs:
Given a lifespan of 15-20 years, CMP would need to be replaced approximately three times over 70 years. Each replacement incurs not just the material cost but also installation and disposal costs. To account for inflation, we'll increase the cost of materials by 2% annually.
Initial installation: $2,000
First replacement (after ~20 years):
Cost per foot with 2% annual inflation: $30 * (1 + 0.02)^20 ≈ $45
Total cost for 24" diameter x 40' pipe: $1,800
Installation cost: $600
Road pack: $200
Disposal: $200
Estimated total cost: $2,800
Second replacement (after ~40 years):
Cost per foot with 2% annual inflation: $30 * (1 + 0.02)^40 ≈ $67
Total cost for 24" diameter x 40' pipe: $2,680
Installation cost: $600
Road pack: $200
Disposal: $200
Estimated total cost: $3,680
Third replacement (after ~60 years):
Cost per foot with 2% annual inflation: $30 * (1 + 0.02)^60 ≈ $100
Total cost for 24" diameter x 40' pipe: $4,000
Installation cost: $600
Road pack: $200
Disposal: $200
Estimated total cost: $5,000
Total cost over 70 years: $2,000 (initial) + $2,800 + $3,680 + $5,000 = $13,480
Heavy Wall Steel Pipe Costs:
Initial installation: $3,600
Maintenance and potential minor repairs: $0 (assumed negligible for this analysis)
Total cost over 70 years: $3,600
Conclusion
While CMP might seem like a more affordable option initially, its shorter lifespan and the associated costs of replacement and maintenance, especially when factoring in inflation, make it far less economical in the long run. Heavy wall steel pipe, with its longer lifespan and lower maintenance needs, offers a significantly better return on investment.
By choosing heavy wall steel pipe, you ensure a more durable and reliable solution for your culvert needs, ultimately saving time, money, and effort over the pipe’s lifespan.
At DK Tanks & Pipe, we are committed to providing high-quality steel pipe and solutions for our customers. When you choose us, you’re investing in long-term durability and peace of mind for your culvert projects.
Credits:
Special thanks to Spittler Excavation for providing data on culvert installation and removal.
Study reference: Dr. Jay N. Meegoda, P.E., Professor of Civil & Environmental Engineering, New Jersey Institute of Technology, and Dr. Thomas M. Juliano, P.E., Department of Engineering Technology, New Jersey Institute of Technology, in conjunction with the U.S. Department of Transportation, Federal Highway Administration.
For an in-depth reference, see the study done by the Bureau of Transportation Statistics (BTS).
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