What is a common size for standard residential sewer pipes?

The typical size for standard residential sewer pipes is indeed 100 mm. This size is commonly used for the main drainage and sewer lines in residential settings, as it efficiently handles the flow of wastewater from household fixtures such as sinks, toilets, and showers. A 100 mm diameter pipe provides adequate capacity to transport sewage while minimizing the risk of blockages, assuming that proper installation and maintenance procedures are followed.

Sizes smaller than 100 mm, such as 25 mm and 50 mm, are usually utilized for specific applications like individual branch drains or vent pipes, not for the main sewer line. Conversely, 150 mm pipes are generally employed in larger commercial systems or when there is a need to accommodate a higher volume of wastewater than is typical in residential applications. Therefore, the choice of 100 mm represents a standard that balances capacity and common usage within residential plumbing systems.