For many people, plumbing and drain system infrastructure are difficult not only to install but also to understand. This article provides some important information that will help make these topics a little less complicated.
Drains are a very crucial part of plumbing.
Most houses in Toronto are connected to municipal sewers, while a small number, especially in rural areas, have septic tanks. The standard size for underground main sewer pipes for an average family home is 4” inside diameter. It is important to note that the size of pipes and fittings are measured by the inside diameter, as opposed to the outside diameter. This is because pipes and fittings have different degrees of wall thickness, and therefore varying lengths of outside diameter. Generally speaking, one 4” pipe will suffice for a house and sewer connection from the basement to the road. The pipe that is installed inside the house and 1 meter from the outside exterior wall is called the building drain. The rest of pipe infrastructure up to the connection with the main municipal drain is called the building sewer. It is very important that every horizontal drain pipe in a house is installed on a slope, since waste water flows out and away from a dwelling only by gravity.
While all residences should have a slope, however, the degree of the slope differs according to the size of the pipe. For pipes up to 3” in diameter, for instance, the minimum slope would be 1/4” per foot; whereas, for 4” pipes, the minimum slope would be 1/8” per foot. To allow for the proper flow of sewage, it is crucial that no sharp changes in direction exist in the drainage infrastructure, and that all elbows are installed correctly with long radius turns. If there are a couple of branches that have to be connected, it is important to use only Y-fitting and 45-degree elbows.
When it comes to waste water, there are two main types of pipes that should be used: PVC (white plastic) and ABS (black plastic) pipes. However, there are some exceptions to this rule. For example, for condo units, plumbers are required to use non-combustible pipes made from either copper or XFR (dark grey plastic). Underground main drains and sewers can be installed with PVC pipes, but the plumbing infrastructure above ground should always be made from ABS pipes. The size of pipes required in a home can be determined by the number of its toilets and load, which is ideally measured by using special units called fixture units. Vertical 3” pipes can serve up to a maximum of six toilets; whereas horizontal 3” pipes should be used for no more than two toilets. Any house with more than six toilets connected to the same soil stack would require the use of 4” pipes.
The installation of vertical drain stack pipes is a bit more tricky.
Because they are placed down into concrete floor in the basement, they must be installed ‘clean-out’ within one meter of the floor. ‘Clean-out’ installation involves the insertion of the removable lid, so there can be access to the inside of the pipes for the purpose of camera inspection. Clearing and inspecting these pipes can sometimes be quite challenging, since construction workers are known to occasionally block their access points by covering them over with drywall.
There are standard pipe sizes for different parts of a house.
3” pipes are used for toilets. 1.5” pipes are installed for kitchen sinks, bathtubs and showers. And, 2” pipes are employed for washing machines. Except when it comes to sloped pipes, standard plumbing codes require the installation of P-trap pipes for every fixture. P-trap is a u-shaped pipe that houses water and prevents sewer gases from entering living space. Every time a tap is used in a house, water is refilled and refreshed in a trap. The floor drain in the basement also has a P-trap installed under the floor and works in a similar way.
If a bad odour ever emerges from the floor drain, the first method of treatment is to pour water into the trap to make sure it is not dry (i.e., trap water sometimes completely evaporates). Current plumbing codes specify that ‘primer tube’ must be installed and connected to the laundry faucet, which discharges small amounts of water during use. Most of the time, this is sufficient to maintain normal water levels in the trap. It is important to note that vent pipe should be used for every trap to ensure negative pressure inside the pipe does not remove all the water from the u-shaped fittings. Moreover, multiple vent pipes should be connected to the main vent stack, which is extended and terminates above the roof. It is similarly crucial to properly support the drain branches, since pipes can decrease in strength over time. In the case of horizontal pipes, support is equally as important and must be at every four feet.
Water distribution systems are a little less complicated, since there are less codes associated with them, as opposed to drains. This is because water in a residence receives its essential pressure from city pipes, which both enable it to change direction multiple times and allows it to run through many different vertical and horizontal offsets. For an average family home, the minimum size of an incoming supply line should be at least 3/4” in diameter. For pipes that are connected to a water meter, or a hot water tank inlet, the standard size should also be 3/4”. Relatedly, the cold water supply for heaters must have a shut-off valve. During the installation of new pipes, it is important to remember that hot water is always found on the left and that cold water is always found on the right.
When it comes to plumbing fixtures, it is sufficient to have half-inch branches. For lawn sprinklers, the outdoor line should be 3/4” or 1”. Equally important, every sink, toilet, bidet, dishwasher, fridge, and washing machine should have their own individual shut-off valves. Current plumbing codes also require that mixing valves be connected to hot water tank outlets. The temperature inside a tank should be around 70 degrees centigrade in order to prevent the growth of harmful bacteria. Because our 
skin withstands up to a maximum of 50 degrees, it is crucial that extremely hot water be diluted with cold water so taps and faucets do not discharge water higher than their maximum threshold.
Mister plumber is one of the most well-known and respected plumbing contractors in Toronto and the Greater Toronto Area (GTA). We have earned this reputation in the community over many years by providing high quality drain and plumbing services for both residential and commercial properties.
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