Replacement & Repair
Trenchless Sewer Repair
Trenchless pipe repair can be used on any type of underground utility line such as a sewer pipe, water or gas line. It is most commonly used on sewer line repair or replacement and falls under either pipe bursting or pipe relining. Most people assume that because you are not digging with a backhoe or other machine, this will be a less expensive method, however that is not the case. When you factor in the cost of the equipment for these methods along with the advantages the homeowner will get such as having a sewer line installed without ripping out the landscape shrubs, grass and trees to not removing an omni-stone or concrete driveway, it is definitely the way to go. Also, a lot of homeowners just do not want all the mess that goes along with digging the trench, such as grass re-seeding and driveway repair. However, we at Keith Miller Plumbing do strive to make the experience of whatever kind of work we do for the homeowner, as pleasant as possible.
Pipe bursting is a method that replaces an existing sewer pipe with a new pipe of the same size or larger. The old pipe is broken and expanded out into the existing soil to make room for the new pipe. The new plastic pipe that is pulled in is called HDPE or High Density Polyethylene pipe. This pipe is very strong, extremely tough, and more flexible than schedule 40 pipe and is as good as or better than any other sewer piping material. HDPE pipes come in several different wall thickness sizes, some up to 1″ thick. Pipe bursting involves digging an entry pit and an exit pit. Once the pits are dug, the new pipe is installed and the pipe is connected to the existing house sewer and onto the sewer main, which is usually at the street.
Static Pipe Bursting
Static pipe bursting is a method of sewer repair that requires a small entry and exit hole, (4X5 approximately). A machine is placed at one hole and a steel cable or chain is run through the pipe to be replaced to the entry hole. A new pipe is attached to a steel cone that is an inch or 2 larger than the existing pipe. The machine attached to the new pipe via a cable to a steel cone, then pulls the new pipe thru the old pipe using brute force. This method will pull around 45 degrees turns providing the cable will go through the pipe first.
Pneumatic Pipe Bursting
Pneumatic pipe bursting is very similar to static except an air-operated hammer is attached to the steel cone and inside the new pipe. As the cone is pulled, the hammer breaks the old pipe at a much faster rate than static bursting. This method is used mainly on hard to break pipes such as cast or ductile iron, or concrete pipe. Also, static pipe bursting can be used to up size an existing pipe for example; from 4″ to a 6″ pipe and from 6′ up to an 8″ pipe in some cases and usually is limited to 100 ft. at a time. Pneumatic bursting does not make turns as the hammer may be up to 6ft. in length. On a larger project, pneumatic bursting can be used to upsize an existing 8″ sewer main to as much as 18″ for a distance of 1000ft. or more at one time. HDPE pipe is flexible, extremely tough, and strong and comes in different thickness, some up to 1″ wall thickness.
Pipe re-lining is used when the existing pipe is still in reasonably good condition but there is a problem of infiltration of the tree roots entering the line or it fails an inspection due to outside water entering into the sewer line. This includes rainwater or ground infiltration.
The pipe re-lining method requires one starting pit, although sometimes can be done through a cleanout with out the pit. It involves inserting a fiberglass sleeve 1/8 to 3/8″ thick from the starting point to the ending point through the existing pipe. The sleeve when purchased is flat, flexible and in a roll. The proper length is cut. Fiberglass resin then coats the sleeve and the sleeve is installed in a machine that forces the new liner into the existing pipe. Heat is then applied in the form of circulating hot water for several hours to cure the fiberglass resin. The liner will negotiate several turns of 45 degrees or more, however the more turns there are a thinner liner may be required to make these turns. This is done so not to cause large wrinkles while negotiating the bends. When finished the new fiberglass will be smooth, watertight and give years of service. Pipe re-lining should not be considered a forever fix, however it should last for 50 years or more. If too thin a liner, not enough resin or improper curing takes places the new liner could fail as in coming loose from the existing pipe or tree roots could grow through the liner material causing a root problem again.