Prefabrication Drawing of House Sewer Main Pipe

The prefabrication drawing of the house sewer main pipe requires special attention to the reserved methods, reserved positions, and other key points to ensure reasonable pipe installation and convenient later use.

Reserved Methods

• Reserved Drainage Branch Pipes on the Ground Floor: Usually, the pipes are directly buried underground, with the main sewage pipe buried in the soil and connected to the outdoor drainage well, while the branch pipes are directly reserved on the ground. This method is suitable for the ground floor and requires the pipe embedding to be completed before ground construction to avoid breaking the ground later.
• Reserved Sewage Branch Pipes for Rooms Above the Ground Floor: Holes need to be reserved on the ground, and the drainage branch pipes are installed through these holes later. This method is suitable for standard floors and requires the confirmation of the kitchen and bathroom positions in advance. PVC pipes are used to reserve the holes to ensure accurate pipe installation.

Reserved Positions

• Kitchen and Bathroom: It is recommended to reserve the kitchen sewage pipes in the corners to save space and facilitate later pipe wrapping. The main sewage pipe in the bathroom should also be reserved in the corner. The toilet reservation should avoid facing the door directly, the floor drain in the shower room should be offset from the sewage pipe, and the washbasin position is generally set at the door or behind the door.
• Hole Size and Positioning: The diameter of the pre-embedded hole for the drainage riser should be 5-10 cm larger than the diameter of the riser. For holes reserved beside the later-built walls, use the blueprint scale or CAD viewing software to determine the position of the later-built walls and then determine the positions of the pipe fittings or holes. Alternatively, positioning can be based on the shear wall. The distance from the pre-embedded washbasin floor drain to the wall should be controlled at 20 cm (considering later plastering), the distance from the toilet to the wall should be about 45 cm, and the center point of the riser should be 15 cm from the wall (flexible adjustment is required considering the thickness of the later plastering or insulation layer).

Other Key Points

• Construction on the Ground Floor and Standard Floors: On the ground floor, pipe embedding should be completed before ground construction. When reserving holes on standard floors, confirm the positions of the kitchen and bathroom in advance and use PVC pipes to reserve the holes to ensure accurate construction.
• Pre-embedding of Outer Wall Sleeves: Special attention should be paid to the pre-embedding of sleeves near the outer walls, such as the reserved holes for air conditioner water outlets and solar collector water supply. The reserved height of the air conditioner water outlet sleeve should be similar to that of the air conditioner socket, with an inner-high and outer-low slope. The reserved holes for the cold and hot water pipes of the solar collector are easily overlooked and require careful inspection. The reserved floor drains and drainage risers near the outer walls should consider the later insulation positions. When installing the outer wall drainage pipes through the outer wall air conditioner platform, carefully read the drawings to avoid missing embeddings. It is laborious to drill and chisel holes for the pre-embedded drainage sleeves on the roof after missing embeddings, so early planning is required.