A horizontal toilet drain is a type of plumbing drain that is installed horizontally, typically below the floor, to carry wastewater from a toilet to the main sewer line. Vent pipes are essential for proper drainage and to prevent sewer gases from entering the home. Without proper ventilation, the toilet may not drain properly, and sewer gases can cause unpleasant odors and health problems.
There are two main types of horizontal toilet drains: wet vents and dry vents. Wet vents are connected to the drainpipe and allow wastewater to flow through them, while also providing ventilation. Dry vents are not connected to the drainpipe and are used solely for ventilation. The type of vent that is used will depend on the specific plumbing system and the local building codes.