Recently Balkan was hired to repair a broken house sewer in Brooklyn. Which was nothing too unusual because subsurface plumbing repair work is needed all the time in NYC. Many of the underground utilities and service lines of New York are very old, and many are disrupted every year by associated underground excavation work. What made this particular drain repair unusual was that previous work by a sewer contractor had been done in a completely unprofessional and improper fashion.
Upon excavating down to the city sewer it was determined that the previous repair had actually broke off and literally sunk right through the public sewer. It seems that when the sewer repair was originally done the plumber cut a hole into the top of the city sewer, shoved on some pipe, and connected back the house sewer line using improper fittings. Thinking it would make this crummy repair better, the plumber then encased the whole mess in concrete. Unfortunately the plumber did not encase the city sewer in concrete to support all the added weight. This type of connection is referred to a ‘riser connection’, but this one was not made properly or to code.
As years past the added weight of the repair encased in concrete and placed directly over the clay public sewer pipe began to create stress and slowly settle. At some point the concrete encased connection settled right through the city sewer and actually caused problems for other houses on the block as well. To correct the problem and perform a correct repair of this Brooklyn house sewer line Balkan had to actually remove three sections of the city sewer. Then three brand news sections of clay pipe had to be installed, one of which contained a new connection for the house that had the broken line. Finally the entire connection and new sections of the sewer were encased with ready-mix concrete to ensure that the repair would be long-lasting and to code. The DEP was called to the site to the site for an inspection and the job was signed-off – Something the previous plumber most certainly did not do.
Something about trust and integrity
For many homeowners and property owners hiring a contractor to perform plumbing work that gets buried is a matter of trust. Sometimes that trust can get betrayed and result in even more costly plumbing repairs down the road. There are basic things to ask a contractor for whenever work is required.
- Certificates of insurance.
- Plumbers License verification.
- Copies of all required permits.
- Certificates of inspection.
- Copies of sign-offs.
In addition taking a few minutes to check on-line reviews, ask for references, and how long the company has been in business continually under the same name are very good steps. You may think think this tedious and unnecessary, but it sure beats the heck out of having to pay for fix a collapsed city sewer caused by shoddy work.
What is a riser connection?
A riser connection is a vertical connection built on top of a public sewer typically meant for a house connection. Depending on the size of the public sewer different design standards are used in the construction of such a connection. It is usual for such a connection to be built when the depth of the public sewer is greater then 13′ or so, or if a groundwater condition exists. In these two cases it is meant to alleviate the cost to property owners of having to excavate to great depths or through groundwater in order to connect properly to the main sewer line.
A riser is also required when the difference in elevation from the point where the house drain exits the building to the city sewer is greater than the pitch that is allowed to be used. As sewers work on the principal of gravity, pitching the pipe is used to so the waste water runs off properly – However only a maximum of 1′ of pitch is permitted for every 4′ of run of pipe. Therefore a riser must be built sometimes when the difference in elevation is too great. Risers must always be one size greater than the size of the connection size from the building – Therefore in NYC where the minimum size of a sewer connection is 6″, the minimum size of a riser is 8″.
When a riser must be built they are carefully inspected by DEP field personnel and must conform exactly to approved plans. All risers must be encased with an approved ready-mix concrete to ensure a long-lasting installation. After the connection is signed off by the DEP the maintenance and ownership of it reverts back to the city. All such installations are built with a clean-out on the top as a means to clean out any possible future stoppages.
Although most sewers in NYC are approximately 11′ or 12′ deep and typical spur connections are used – There are sewers that are in excess of 25′ deep and they usually have carefully constructed riser connections on top of them.