Waterstop construction method (expansion waterstop construction method)

External wall waterstop (external wall waterstop construction method)

Rubber waterstop joint (Ruber waterstop joint construction method)

Kitchen and bathroom waterproofing strip (height of kitchen and bathroom waterproofing strip)

Water-swellable rubber waterstop (expandable rubber waterstop strip)

What is the purpose of waterstop (Is the purpose of waterstop significant)