Hygrothermal Protection

High-performance heat & weather protective materials for tropical climates must have four beneficial and essential functions – heat resistance, water resistance, mold resistance, and the right level of vapour permeability.


Understanding vapour permeability

Vapour permeability is probably the most ignored and least understood of the four. Yet, it can have the greatest impact on how a wall system performs. Bioclimatic Solutions materials are Hygro functional (in the same time, vapour-permeable “breathable” and water sealant). They allow water vapour transfer while blocking liquid water.

Vapour sealant


Air sealant coatings block air circulation not allowing the wall to "breathe" and thus unable to eliminate moisture from masonry and concrete structures. The moisture remains trapped between the wall and the coating, increasing the heat transfer in the building, causing cracks and other problems in the long run.

Vapour permeable



Often referred to as breathability, vapour permeability describes a material’s ability to allow water vapour to pass through it.  Unlike bulk water holdout, which refers to water in its liquid form, vapour permeability concerns water in its gas form.

The accumulated moisture in masonry and building structures can be eliminated in time due to the process of vapour diffusion. Once the moisture is eliminated there is no more vapour diffusion. The walls are dry and have achieved there maximum thermal resistance.





The most important benefits of Hygrothermal protection

  1. To prevent mold and algae formation due to condensation

Moisture (e.g. water leaks, high humidity) is really the key cause of dampness in the walls. Mold and algae growth are the effects of further deterioration. In tropical climates, this deterioration is further increased by:

- Surface condensation because of the differential temperatures between the internal and external environments
- High organic content in the air-sealant coatings

  1. To eliminate thermal bridges


Thermal bridges are portions of masonry where different materials with different insulating capacities are used, creating "thermal discontinuity" that favors thermal dispersion. Concrete pillars and beams are a classic example of thermal bridge. Thermal bridges are one of the biggest causes of heat dispersion in buildings. Failure to correct them can give rise to condensation and extra heat load up to 40%.

  1. To reduce air-conditioning consumption

Thermal mass is a term that describes the ability of a material to store heat. Concrete and masonry products do this well and, being dense materials, can store a lot of heat. They absorb heat during the day, conducting it inwardly and releasing it during the night. The BES having the ability to dissipate heat, it responds naturally to changing conditions. It helps to stabilise the internal temperature and provides a largely self-regulating environment, protecting from overheating and reducing the need for mechanical cooling (active cooling)


Bioclimatic Solutions Pte Ltd -1 Sunview Road, Eco-Tech @ Sunview, #06-04, Singapore 627615, Tel. (+65) 6262 0571