Corrugated Metal Pipe Repair with SprayWall®

Even though most people don’t see it or know how it works, underground infrastructure is critically important for the daily functions of our lives. 

From underground pipes carrying drinking water throughout cities to corrugated metal pipes channeling drainage beneath highways in the country, these hidden structures keep us going. 

So, how are these underground pipes and structures repaired?

There are a couple of different approaches: digging from the surface to the underground problem or trenchless repair.

Digging from the surface is expensive, causes traffic disruptions, and takes a long time to carry out. 

Trenchless repair—on the other hand—costs a lot less, can be completed within a few working days and saves residents the trouble of traffic disruptions. 

SprayWall®  is a long-lasting, peer-reviewed trenchless repair solution that is scientifically proven to seal underground pipes AND increase their structural integrity. 

It was put to the test in a recent study conducted by the University of Texas at Arlington. The results helped create industry testing standards and prove just how strong SprayWall® really is. 

The Challenges of Underground Infrastructure Repair


Obviously, reaching underground pipes is not easy. 

As we mentioned, there are two ways to approach repairs. You can either attack them from the surface by digging down to the damaged pipes, or you can fix the pipes directly underground.

We’ll start with the challenges of repairing from the surface. 


Digging to the pipes

Addressing underground repairs from the surface comes with a lot of issues.

To start, roads usually have to be blocked off so construction crews can get to work. This is a lengthy process that can snowball into all sorts of delays and disruptions for the local community. 

Additionally, repairs from the surface are lengthy. They can take days or even weeks to complete, as roads have to be ripped up, the pipes have to be fixed, the sediment has to be filled back in, and the road has to be paved over again. 

Even worse, there’s the looming possibility of rework, as surface repair solutions often only last ten years or so.

Municipalities don’t want to leave their residents or workers irritated by any of these issues and want to avoid expensive rework projects when the job doesn’t get done well the first time. 

Frustration, inefficiency, and ineffectiveness are all symptoms that come to mind. 


Trenchless repair

Though trenchless repair is a much more cost-effective solution than digging from the surface, it comes with its own unique set of challenges. 

Most of these challenges are technical, from figuring out which pipes can be accessed via underground access points to identifying the spaces that are large and safe enough for humans to work in. 

Plus, trenchless repair operations require highly trained experts and specialized equipment. 

However, it’s worth it. 

When they’re possible, trenchless repair solutions save municipalities countless hours and dollars over the long run, with solutions that hold up for decades. 


Fewer Headaches: Trenchless Underground Pipe Repair

As we mentioned, trenchless underground pipe repair operations are complex, but they’re worth the investment.

Trenchless projects can be carried out to completion within a few working days, far shorter than digging from the surface. 

Plus, solutions like SprayWall® last a lot longer and are less likely to require repairs and rework.

SprayWall® lasts over 50 years and cures completely within 72 hours of application. It begins to gel within 8 seconds and is tack-free after two minutes.

This means trenchless repair crews who use SprayWall® will likely be done with the entire project in the time a digging crew would need just to dig up and bury what they’re working on. 

The advantages of going trenchless and using SprayWall® go beyond just efficiency and cost-effectiveness, however. 

SprayWall® is scientifically proven to increase the structural integrity of underground infrastructure, with test results that help shape what success means in the industry.  


UTA Puts SprayWall® to the Test

The University of Texas at Arlington recently completed a study of spray-applied pipe liners in gravity stormwater pipelines, utilizing our SprayWall® product as one of their test formulas.

SprayWall® was the only polymeric product to participate in this innovative test. The other test material was a cementitious spray-applied liner.

Both products were applied to invert-less corrugated metal pipe culverts that were put through stringent ring compression testing in the UTA’s Civil Engineering Lab’s Soil Prism Test Bed.

According to the study, SprayWall® not only sealed the test pipes but also increased their structural integrity by up to 800%, four times stronger than the cementitious mixture. 

The study also concluded that SprayWall® was considered structurally capable of acting as its own replacement pipe inside of the test pipe. 

As stated in the report: “…Since the polymeric SAPL did not crack at the invert-cut location, even at the ultimate loading stage, it can be concluded that the polymeric liner was structurally capable to perform as a new pipe inside the host pipe (i.e., pipe-in-pipe) and could solely resist the applied ring compression.”

This study officially proves what we’ve known for decades: SprayWall® is the solution for corrugated metal pipe repair.

Read more here.


Setting Industry Standards

Prior to this study, there were no official design or testing methodologies for spray-applied pipe liners. 

SprayWall®’s performance helped create them, as the results of the study were used to develop testing and application standards for spray-applied pipe liners in DOT markets across the U.S.

What does this mean for underground infrastructure repair operations? Increased confidence for everyone involved. 

Infrastructure contractors can have the confidence of knowing they have an industry-defining product that’s backed by peer-reviewed scientific studies and decades of results. 

Meanwhile, civil engineers and asset managers can trust the products that the contractors bring to the job, knowing they’re proven both in the field and in the lab. 



Sprayroq engineers working in a shop

Underground infrastructure is vital to our society, so it’s important that we keep it protected. 

Trenchless repair methods for corrugated metal pipes are proving to be a superior solution when applicable, as they save communities time and money through long-lasting solutions and minimal disruptions. 

Our SprayWall® Polyurethane Lining System is especially effective at not just sealing damaged underground pipes and structures, but actually increasing their structural integrity.  

SprayWall® is minimally invasive and saves engineers, contractors, and communities their time and money. 

It cures in minutes, and reaches its final cure within 72 hours, with a designed service life of over 50 years. Whoever works on the project will likely be in retirement by the time further repairs are being discussed. 

Plus, it’s scientifically proven to strengthen the structure of underground pipes, with test results that quite literally define industry success. 

Have questions about SprayWall® or want to learn more about becoming a Sprayroq™ Certified Partner? 

Contact us, and let’s work together to keep underground infrastructure protected for decades to come.