Current location - Health Preservation Learning Network - Slimming men and women - There is a black plastic ring on the wall in the stairs. What is it?
There is a black plastic ring on the wall in the stairs. What is it?
This is waterproof coiled material.

Waterproof membrane is mainly used in building walls, roofs, tunnels, expressway, landfills and other places, which can resist the leakage of rainwater and groundwater. As a leak-proof connection between the engineering foundation and the building, it is the first waterproof barrier of the whole project and plays a vital role in the whole project.