Water-proof

Water-proof or water-resistant describes objects relatively unaffected by water or resisting the ingress of water under specified conditions. Such items may be used in wet environments or under water to specified depths. Waterproofing describes making an object waterproof or water-resistant

Divide to be Metal & Concrete.

Metal

Water-proof 1

Concrete

Water-proof 2

link source : https://www.definitions.net/definition/waterproofing