The building envelop is generally considered as our third skin. Moss growth and mold growth are constrains which reduce the strength of the third skin. This study is aimed to analyze the effect of the mold growth and moss growth on different walling materials such as Brick, cement blocks, cement stabilized earth block, Cabook, Mud concrete blocks, Geo polymerized earth blocks walls and plastered walls with cement plaster and rough finish plaster in a tropical climate. Organic matter, surface roughness, water absorption capacity, sorptivity and the capillary action of those walling materials were studied first. After which mold growth and moss growth were conducted in the real world controlled environment to accelerate the mold growth and moss growth. The growth rate and the strength reduction due to the effect of mold growth and moss growth were studied. The results demonstrate that walling materials with high porous spaces have the high potential to grow moss and mold. The walling materials with the high organic matter also encourage moss and mold growth. Interestingly it was found that even though materials like mud concrete block and geo polymerized earth blocks have high organic matter, their less surface roughness helped to reduce the moss growth and mold growth. And also, plastering can emphatically reduce the speed of mold growth and moss growth.
Udawattha, C., Galkanda, H., Ariyarathne, I. S., Jayasinghe, G. Y., & Halwatura, R. (2018). Mold growth and moss growth on tropical walls. Building and Environment, 137, 268–279. https://doi.org/10.1016/j.buildenv.2018.04.018