Perhaps you've heard that your municipality or private contractors are doing something called chemical grouting to fix the sewer pipes near you. You're not sure what this means for you and want to make sure it won't have a negative impact. Here's the scoop on chemical grouting, why it is used and what its benefits are.
What is Chemical Grouting?
Chemical grouting is a technique to repair aging sewer pipes that might have cracks or failing seals at the joints. As many as 240,000 water mains break or crack every year in the U.S., which allows groundwater to come into the pipe or sewage to leak from the pipe, contaminating lakes and rivers nearby.
Going down into the ground, digging up the pipe and repairing it is definitely an option if things look really bad, but that gets very expensive.
Instead, the chemical grouting process allows workers to inject a non-toxic polyurethane compound that reacts with the water and soil to form a rubber-like substance along the exterior of the pipe. This effectively patches the pipe and allows it to function normally for a longer period of time, reducing costly repairs.
When is Chemical Grouting Used?
Most sewer repair companies and municipalities now have cameras that can show workers the extent of any damage or leaks. A pipe that has structural breaks is not a good candidate for the use of chemical grouting; it's most commonly used where joints are leaking.
Any pipe that is going to be repaired through chemical grouting should also not have problems like penetration of tree roots or other debris inside that can keep the grout from working properly. Finally, there has to be an opportunity for the grout to flow out of the cracks or leaks in the pipe and into the surrounding soil, where it can make an effective barrier outside the pipe instead of clogging up the inside.
Chemical grouting is also used to reinforce pipes that risk moving due to excavations or construction nearby, or that could fail because of other ground movement nearby. The procedure for reinforcing a pipe with this type of chemical grouting is slightly different, as the material is generally injected around the outside of the pipe instead of from the interior through cracks or leaks.
How is the Grout Applied?
Techniques for injecting chemical grouts are updated as new technologies become available, but the traditional way to accomplish this is through use of packers. Packers are inflatable plugs that can be put into a pipe and inflated, forcing the grout through the leaks and cracks into the outside soil. Workers can do this without digging up or around the pipe, through the use of small cameras and remote controls to inflate the packers. This technique works well for pipes up to 144 inches in diameter.
In short, chemical grouting is a time- and money-saving technique that will repair sewer pipes without introducing toxic chemicals to the system. Talk to a sewer services company or plumbing expert like All Clear Pumping & Sewer if you have questions about the process and how it is done.