1.Rainwater pipes should be installed according to the design’s location. Suspended pipes should be installed horizontally without slope.

2.Inspection ports should be installed on rainwater risers as specified, with the center of the ports 1.0 m from the ground. When using high-density polyethylene (HDPE) pipe, the maximum spacing between inspection ports should not exceed 30 m.

3.Connecting elbows between rainwater horizontal pipes and risers, and between risers and discharge pipes, should use two 45° elbows or 90° elbows with an R ≥ 4D.

4.Where rainwater pipes pass through walls and floors, sleeves should be installed as required.

5.During installation, open openings in pipes and rainwater gullies should be sealed.

6.Suspension systems should avoid crossing building settlement joints and expansion joints. When this is unavoidable due to site conditions, appropriate measures should be taken based on the characteristics of the system pipes and the deflection of different pipe materials.