Balcony Insulation and Condensation

Cantilever balconies are commonly seen protruding from the façade of condominiums and apartments.   However, this arrangement can lead to problems arising from heat transfer and condensation, resulting in mold growth.

Typically, steel framed cantilever balconies have beams that extend into the building and connect to the structure.   Concrete balconies are usually cast integrally with the rest of the floor.  During winter months, the exposed balcony structure becomes cold and when it meets the warm building interior, typically near a sliding glass door, thermal transfer increases, as does the possibility for condensation and mold growth. Building owners should be aware of this possibility and watch for condensation forming in the area under the carpet or wood flooring, near the balcony.

Fortunately, for new buildings with cantilever balconies, products are now being produced to prevent condensation and mold by inserting a thermal break (insulation) between the exterior and interior portions of these structures.   These new balcony structural inserts can carry significant weight, while preventing interior heat transfer.  The most common materials used for these products are stainless steel and fiberglass reinforced laminate composites.  Although these are new products, they appear promising.