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Everything You Ever Wanted To Know About Sewers (And Then Some)


Whether you are a home owner or a manager of a building, a sewer back up is something you would like to avoid at all costs. A sewer back  up is messy, unhygienic, and expensive to clean up. Unfortunately, over time, sewer line clogging is a fact of life.  Having a professional company like CF Plumbing, Inc. preventatively cable your sewer lines can help prevent major problems, but as sewer lines age, you may need to have them excavated and replaced.  The following article covers everything you need to know about your sewer drains, and probably some things you didn’t want to know.


What causes a Sewer Backup?


  • Blockage from tree root infestation is the most common cause of a stopped or clogged sewer line. Root growth is a continuous problem; it can be temporarily abated with cabling, which is made more effective with the concurrent use of chemicals, but it cannot be stopped unless the tree is removed or a new line is installed. Root infestations only get worse over time. Preventative cabling will become more frequent with time until the roots eventually cause the sewer line to collapse requiring the line to be excavated and repaired or replaced.

  • A grease blockage inherently occurs in waste or sanitary lines and is introduced into the line from the kitchen sink, dishwasher and garbage disposer. When a line packed with grease is cabled out, it is impossible to determine how much grease is in the line. Once the cable opens the line it is assumed that we are complete with the job. If however the drain line is packed with grease, the grease will droop, closing the hole made by the rodding work, thereby stopping up the drain line again. If this occurs, additional work is required to open the drain line and attempt to find a solution to lessen the frequency of grease line stoppages. Grease stoppages can be prevented by the installation of a grease receptor, periodic cabling or jetting, use of preventative maintenance chemicals specifically designed for grease, and a reduction of grease and oil products placed in drains.

  • Many people are not aware of what kinds of food matter they can and cannot throw down their disposer or how to use the disposer properly. First, when running the disposer, always run cold water before and at least two minutes after grinding is completed to wash the food waste down the drain line. Second, grind up food in small batches, allowing the food to wash down the drain line, preventing the disposer and drain line from becoming stopped up. Finally, avoid grinding up the following types of food: corn husks and cobs, onion peel, artichoke leaves, banana peels, celery, or any other fibrous foods.

  • Mud can enter sewer lines from driveway or area drains and yard waste can enter drain lines from dirty gutter lines. Because neither mud nor organic matter will break down into a liquid form like sewage, this matter tends to accumulate and create a stoppage. The only way to prevent these types of stoppages is to keep driveway drains and gutters clean, and perform preventative cabling maintenance on those lines.

  • Many people do not realize that sanitary sewer lines are designed to accept toilet paper and human waste ONLY. If you flush anything else down the drain line, regardless as to what the manufacturer of those products states, you are asking for trouble. Do not flush the following items down your sewer line: feminine sanitary products, dental floss, Q-Tips, prophylactics, Handi-Wipes; Baby Wipes, diapers, dead goldfish (or other small deceased pets), paper towels, facial tissue.

  • A blockage caused by broken or collapsed lines usually occurs with age and is normally caused by interaction with tree roots, settling of the earth or settling of the building. A broken or sheared sewer line is usually found by pulling mud back on the end of the cable or an inability of the cable to go any further into the sewer line. Once a sewer line has broken, the only remedy is to insert a sewer camera into the line to determine the true cause of the problem, the location of the problem and the condition of the line up to the point of the problem. The decision to repair or replace the sewer line and the cost associated with the work cannot be determined without first inspecting the sewer line.

  • A broken line will slowly accumulate waste matter flowing down the pipe until the line stops up. Once we determine that a drain line is broken, there is no way to determine how long the line will remain open or how much time it will take before the broken line worsens, making an immediate dig and repair necessary.

  • Sewer lines will sometimes sag. This happens when the ground underneath the sewer settles. When the ground moves, the sewer line no longer has the standard, steady ¼” drop per foot but will create a sag or belly that will trap waste and water. When waste becomes trapped in the sagging portion of the sewer pipe, that waste will harden and slowly accumulate until a line stoppage occurs. Normal sewer cabling will usually remove the stoppage and clear the sewer line but this will only be a short lived temporary solution. Only a dig and replacement of the sagged sewer line can provide a longer lasting repair.

  • Less common are blockages caused by malfunctioning check valves or back flow preventors. Repair or replacement of these devices along with annual maintenance should help to eliminate problems.

  • It is not uncommon to have a sewer line break our sewer cables while trying to open a sewer line. Unfortunately there is no way to determine from the onset the severity of a sewer line stoppage or if the sewer might break our rodding cables. If a sewer cable breaks in the sewer line sometimes the lost cable can be retrieved with a special retrieving head that is placed on the end of a sewer cable. If cables are stuck in a sewer line we can sometimes free the cables with a more powerful machine, by pulling on the cables or by waiting for the tension in the cables and the stoppage to relieve and release the cables. If stuck or broken cables cannot be retrieved or freed from the sewer line, the sewer line must be excavated to remove the line stoppage and cables, repairing the sewer line.

  • Finally, many sewer problems are exasperated by the fact that more than one problem can exist with a sewer at the same time. Sewer problems are remedied on a trial and error basis and only one problem is found and fixed at a time. Once the first problem is taken care of, only then can we determine if a second problem exists and so on. Unfortunately, the customer perceives that the field technician has misdiagnosed the problem or has not fixed the problem when in reality the sewer is showing us that more than one problem exists or that the problem is bigger than can be remedied by cabling alone.


Remember that cabling a sewer line is only a cure for a sewer line that is stopped up due to improper debris or a build-up of debris in the line. Cabling cannot cure sewer lines that are broken, sheared, sagging, infested with roots or are piped improperly.



How is a Sewer Line Cleared?


The clearing of a sewer or drain line is not as simple as inserting cabling equipment and turning on the machine. There is quite a bit of diagnostic work that coincides with the knowledge of how building sewer and drain lines are SUPPOSED to be installed in home. The procedure is as follows:


  • Find the floor drain(commercial) or fixture(residential) that is showing the symptoms of a sewer stoppage.

  • Determine which fixtures are served by the blocked line.

  • Determine if the stoppage is in a branch line or a trunk line.

  • Determine the best location to cable from.

    • Where is the largest cleanout?

    • Which cleanout will allow access to the largest portion of the drain line

    • Which cleanout will get the cutter head closest to the blockage to transmit the largest amount of power to break through the stoppage.

  • Determine if a second person is required to help cable to prevent damage to customer property or prevent injury of the cabling technician.

  • Determine the type of cable machine and cable to use.

  • Determine the best type of cutting head to use.

  • Determine if the sewer line has to be drained before removing a clean-out plug that could otherwise cause water damage.

  • Begin cabling.

  • Note the distance that the sewer line opens.

  • Note the distance of any spots in the sewer that cause resistance to the cabling.

  • Continue cabling until the city main or trunk line is reached.

  • Extract the cables noting the distance of any hard spots.

  • If any hard spots still exist in the sewer line, continue to work the cutter head back and forth over the hard spot.

  • Extract the remaining cables, noting the type of debris, if any, extracted from the sewer line.

  • Seal the clean-out plug and pressure test if possible.

  • Test the sewer line to determine if the drain line is open.

  • If the sewer line is open, we have to assume the cabling has been completed successfully.

  • After the sewer line is cleared, we recommend having our technician camera your drain line to see what caused the blockage and if there are any other problems to detect.



Maintaining Sewer and Drain Lines


There are several methods available for opening and maintaining sewer and drain lines including:


  • Cabling is a term used to describe the most common method used to open a slow or stopped drain line. Cabling equipment usually consists of cabling machine, cables and a cutting head. There are many different cutting heads designed for different types of drain lines that alleviate certain types of sewer and drain line stoppages. The cutting head attaches to the end of a cable that is inserted into the sewer or drain line. The cables are sectional and come in different lengths and diameters for different types of lines and stoppages. All cables look like long springs. The cabling machine consists of a motor and clutch to grab and spin the cables and cutting head at a low speed but at a very high torque. The spinning cutter head will cut through the different stoppages in an attempt to open the line. The coils in the cable help to feed the cable into the sewer line as the cable spins and to snare the debris stopping the line to help remove the debris from the line.

  • Jetting is a term used to describe a method used to open and scour drain lines with the use of high-pressure water. A jetter uses water pressurized between 2000 to 6000 psi to cut through small root fibers, dirt, organic debris, grease and oil. Jetters are commonly used in restaurants and auto garages where grease from kitchens and oily sludge from automobiles collects in drain lines. While cabling can open a drain line coated with grease or oil, only a jetter can scour the line removing the majority of the grease and oil.

  • Video inspection is used to determine why a sewer or drain line has a problem. Most cameras are designed to inspect sewer lines from 4″ to 8″ in diameter. The camera head is attached to a stiff fiber-optic line, which is pushed into the sewer. The head of the camera is illuminated with LED’s (Light Emitting Diodes) to provide a light source for the camera. Sewer cameras cannot “see” underwater as the water is rarely clear which causes the LED’s to reflect off of the debris in the murky water. Once the camera operator has positioned the camera to view the source of the problem, the problem has to be located above ground. A transmitter imbedded in the head of the camera allows the camera operator to locate the camera head above ground. The locating process is rarely exact because underground electric, cable, telephone, gas, water, sprinkler and other systems, as well as the type of sewer pipe material and sewer depth can throw off the accuracy of the locator.

  • A sewer cleanout is the general term used to describe an access point installed in a waste piping system to allow access to the system for cabling maintenance. All homes should have a readily accessible cleanout for cabling. Most homes in this area have a 4″ diameter sewer line exiting the house, which makes for the best clean-out location. There are benefits of having an outside cleanout.

    • Cabling work is performed easier and quicker if performed outside. Equipment does not have to be brought into the home, up and down stairs, into crawl spaces or on top of a roof.

    • If the home has an overhead sewer, the cleanout must be opened slowly allowing all of the sewerage that is inside the sewer to be slowly drained from the sewer before we can completely remove the cleanout cap and begin the cabling work. This is time consuming (and therefore more expensive) and can potentially be very messy.

  • Preventative cabling maintenance is performed to keep the myriad of sewer and drain lines open and flowing. Consumers ask us how often they should have their sewer cabled to prevent a sewer back-up. Unfortunately it is impossible to tell. Preventative cabling frequency is usually determined by historical information. If the customer finds that the sewer typically stops up once a year, then cabling once every 6 to 8 months would be prudent. Just remember that as time goes by, the problems in the sewer will become worse, requiring more frequent cabling maintenance.

  • Excavation has to be performed for several reasons:

    • The sewer line cannot be opened by cabling.

    • The sewer line has so much debris that the cables or video camera head have become entrapped in the sewer. Usually the only way to retrieve the equipment and open the sewer is via excavation.

    • To install a sewer cleanout to allow for more effective, safer, or less liability for damage to personal property during cabling.

    • To make a spot repair of a sewer line.

    • To replace a sewer line.

  • Excavations can be performed by hand or with equipment. The decision to use equipment is based on the depth of the sewer line, the number and types of underground utilities that may be in the path of the excavation, and the area surrounding the excavation. If there is not enough room to move equipment to the excavation or enough room surrounding the excavation area then the only alternative is hand excavation.

  • Pipe lining is the latest innovation in pipe repair that molds a new pipe right inside your old pipe without digging trenches. It is a great option when the problem is under patios, driveways, street or other areas difficult to dig. The following illustrations show how the process is done:


It all starts with a visit from our trained installer to assess what the job site requires












The pipe is thoroughly cleaned using a high-pressure jetting process














The liner is installed into the cleaned line













The repaired pipe is returned to full service.



Preventative Maintenance versus Alternative Options


There are many customers who are on preventative maintenance schedules with our company. The idea is to cable a sewer line with enough frequency to prevent the sewer line from backing up into the house. The frequency of cabling maintenance is historically based and differs with every sewer line. We have customers who know from past experience that they need to cable their sewer anywhere from once every other year to up to 4 times a year.

Over time, a sewer will require move frequent cabling maintenance because problems with a sewer line do not get better over time, they get worse.

When a customer reaches the point where they require preventative cabling maintenance two or more times a year, we will usually suggest inspecting the line with our sewer camera to determine the type of problem and the cost for a long lasting solution.

At this point the customer has to decide how much longer they intend on living in the house and calculate the maintenance cost versus the repair. Other considerations should include the risk of damage when a sewer does backup (if not repaired) and the value of the home when selling due to a problematic sewer, (Disclosure laws prevent homeowners from not informing prospective buyers of the sewer history.)


When is Excavation or Pipe Lining Necessary?


  • If preventative cabling maintenance is rarely performed, roots will have the opportunity to overgrow the sewer line and debris will be allowed to accumulate to the point where rodding takes an inordinate amount of time to perform. If rodding for more than 3 hours with several different types of cutting heads is removing debris but not opening the line, at some point a decision has to be made. Because no one can see underground, it is impossible to determine the extent of the debris or how much of a stoppage has been ground through and removed and how much of the stoppage remains. For example, assume that a root growth is 10′ long inside a sewer and we spend 3 hours rodding. We may have successfully removed 9′ of the stoppage or we may have removed 1′ of the stoppage. What are we to do? Do we continue in hopes of removing the last foot successfully, or continue wastefully when we should be excavating instead. Sometimes a customer will become frustrated and call in another company in an attempt to open the line. If the first company removed 90% of the stoppage but did not clear the line and a second company arrives, removing the last 10% and opens the line, the first company, which did the majority of the work is considered a failure while the second company, who performed little work in comparison is considered the hero.

  • When we cable a sewer line and we hit an obstruction, we will typically extract our cables and re-try the cabling process two or three times before having to look at excavation or pipe lining for a solution.

  • Sometimes when the cables are pulled out of the sewer for inspection, mud or clay is found on the cutting head. When a sewer line breaks, sometimes rain and groundwater will slowly wash mud and clay into the sewer line, eventually causing an obstruction. When the cable is inserted into the mud filled sewer line, the clay will impact itself onto the cutter head. This is a clear indication that the sewer is broken and must be excavated for repair.

  • Not all sewer lines can be opened with cabling equipment. When a sewer line collapses, shears, or a root infestation is too large, your options are: excavation and replacement of a portion of or the entire sewer line; or the latest technology in pipe lining.


Have a professional company like CF Plumbing, Inc. maintain and inspect your sewer lines periodically.  This type of preventative maintenance is the best way to keep your sewer lines open and flowing, and reduces the risk of a messy, inconvenient and expensive flood. If you have any questions about sewer line back-ups, we’ll be happy to come out and take a look at your sewer lines, and advise you on the proper action to take.

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