Which of these most accurately describes waterproofing?

Waterproofing is accurately described as treating the surface to prevent the passage of water under hydrostatic pressure. This process involves using materials and coatings that create a barrier preventing water from penetrating through surfaces, which is essential in keeping structures dry, especially in areas prone to water exposure.

The focus on hydrostatic pressure is particularly important because it refers to the pressure exerted by standing water, which can push water through any unprotected surfaces. Effective waterproofing is therefore critical in preventing leaks and water damage in roofing systems and basements.

Other choices, while related to building integrity, do not define waterproofing. Insulation primarily deals with thermal performance rather than moisture protection. Sealing joints reduces air infiltration but does not directly address water passage in the same way waterproofing does. Installing drainage systems can manage water once it has penetrated a roof but does not prevent water from entering in the first place, which is the primary purpose of waterproofing.