Elastomeric Membrane

Many of Hawaii’s parking decks and lanais either lack an elastomeric membrane to mitigate water intrusion (and dissolved chloride ions) into the concrete or else the existing membrane has simply failed over time due to wear and tear or perhaps abuse.  Absent an effective protective coating, Hawaii's slightly saline rain water migrates through the concrete to the reinforcing steel and promotes rusting and subsequent concrete delamination or spalling.

Most are aware of the appropriateness of applying a membrane on the top of parking decks to mitigate water infiltration through either slab cracks onto cars below or to mitigate concrete spalling.

An often overlooked situation is the lack of an elastomeric membrane on a lanai deck beneath a tile installation.  To whatever extent the tile itself may be impermeable to water infiltration (e.g. a hard fired glazed tile), the grout joints between tiles are almost always a medium for water to soak through and onto the underlying concrete surface.  Once water infiltrates to the top of the concrete, the overlying tile acts as a 'cap' that does not allow the slightly saline water to evaporate.  Instead it soaks into the concrete.  Many are the lanais where there is concrete spalling below a tile installation either because a membrane was not applied or the tile contractor was allowed to install a cheap membrane for cost considerations.  At some point the expanding, rusting rebar not only causes the tile to buckle, but also allows water infiltration onto the lanai below.  For the sake of the occupant below if for no other reason, we are of the opinion that condominiums should not allow a unit owner to install lanai tile absent an effective membrane. 

RCM Construction has applied elastomeric membranes in all of these conditions.

Other Concrete Coating and Waterproofing Concerns 

Aside from parking decks and lanais, there are multiple situations where a coating or waterproofing is a necessity.

Whatever may be your job specific problem, RCM Construction can likely resolve it.