A coating is a system, not a single layer
Why the watertightness of a tank, a pool or a raft is decided at the coating, at the substrate, and at every singular point.
A bonded waterproofing system typically has a prepared concrete substrate, a primer, a membrane, and a protection or wearing layer. The membrane may be a sprayed polyurea, a bituminous sheet or mastic, or another fully bonded system specified for the exposure.
Failure often starts at a singular point (a penetration, an upstand, a joint or a change of direction), or under a wearing course that hides the membrane. The absence of a visible leak is not proof that the system is sound: water can travel under the membrane and appear far from the defect.
The same questions recur on aquarium tanks, architectural and hotel pools, marine and coastal concrete, basement rafts, and buried decks: was the substrate prepared for the system, were the application conditions respected, and how are penetrations, joints and upstands detailed?
MAREX inspects and specifies waterproofing coatings, including polyurea and bituminous membranes of the type used on aquatic and marine structures. We look at adhesion, thickness, continuity, overlaps, moisture under the system and the condition of the concrete underneath. We do not sell a branded product line, and we have no partnership or distributorship with any coating manufacturer.
A diagnosis is progressive: simple, non-destructive actions first, then more local openings if the findings require them. That logic is set out in MAREX method sheet D5-1, written for bridge-deck waterproofing and applied here to tanks, pools and other bonded systems. The sheets are listed as method references and are not offered as a public download on this site at this stage.