A sewage line that goes through an area in your landscape that is heavily trafficked can mean problems down the road. While a straight line is shorter, it may be necessary to install some elbows to get the pipes to circumnavigate a patio, play area, or garden. This is important if the pipes rupture, or crack.
It can typically be found in the basement, crawl space or garage. You will want to search for a pipe that is approximately four inches in diameter with a screw cap on the top that has a notch or square knob at the top. Note that some homes have an indoor sewer cleanout point, while others may be located outdoors.
Go to the city office directly or call them to see if they can tell you where the sewer line is located. Usually, they can show you where the line goes from your home to the city's main line. If you are unable to reach the city, see if there is an interactive underground utility map of your area online.
Plastic PVC Pipe Polyvinyl Chloride (PVC)
How long will a sewer line last? The life of your sewer line depends on your pipe's material. Cast iron pipes last between 75–100 years, clay and cement pipes can last up to 100 years, orangeburg pipes last around 50 years, and PVC pipes can last over 100 years.
Unless two toilets are on the same drain and then it must be a 4-inch plumbing waste pipe, the toilet requires a drain pipe of 3 inches in diameter. Unless there is a toilet discharging into the piping, systems with less than nine units can use a 2-inch pipe.
4″ waste line can support 90 DFU's, Toilets can be 3–4 DFU's depending on how many gallons per flush. So, 22 toilets if they use a lot of water.
Requires two vertical stacks with horizontal connections from both sides, or one stack if toilets arranged over two floors, 32 total.
Divide the pipe's internal diameter by 2. For example, if the pipe has an internal diameter of 0.1 meters: 0.1 ÷ 2 = 0.05 m This is the pipe's radius. Square this radius: 0.05² = 0.0025 m². Multiply the result by pi, which is approximately 3.142: 0.0025 × 3.142 = 0.007855 m².
The piping should be the same size as the drain hole: for a 1 1/2-inch drain hole, use a 1 1/2-inch pipe. All bathroom sink piping is readily available at local hardware and home improvement stores. It's best to stick to one size for the sink piping, making sure it will all match.
Referring to the International Plumbing Code, a bathroom group requires 5 Drainage Fixture Units. As a horizontal branch 3" is good for 20 DFU's or 4 bathroom groups.
A standard toilet waste pipe is 100mm in diameter. When a house is built its relatively straightforward to route this large bore pipe from the toilets to the drain, but with all the internal walls up, routing a pipe to a room newly designated for a toilet is difficult.
710.1 Maximum Fixture Unit Load
| DIAMETER OF PIPE (inches) | MAXIMUM NUMBER OF DRAINAGE FIXTURE UNITS CONNECTED TO ANY PORTION OF THE BUILDING DRAIN OR THE BUILDING SEWER, INCLUDING BRANCHES OF THE BUILDING DRAINa |
|---|
| 21/2 | — | 24 |
| 3 | — | 42 |
| 4 | — | 216 |
| 5 | — | 480 |
