Fungal growth on concrete surfaces of floors and walls

. Generally, a high pH-value (above 12) in building structures is considered to be an inhibitory factor against fungal growth. However, fungal growth can in some cases be detected on concrete surfaces in new buildings shortly after commissioning and in existing walls retrofitted with internal insulation installed using cement based adhesive mortars. This paper deals with two building envelope structures: newly casted concrete floors fitted with vapor membranes and existing walls fitted with internal insulation. In both fungal growth has been detected and linked to the decreasing pH-value and lingering moisture. For floors, several new buildings were investigated and the cleaning method, moisture content, concrete age after casting and fungal species were registered. Furthermore, the development in pH-value was measured on newly casted concrete to determine the decrease in pH-value. For walls, laboratory and field experiments were conducted both under realistic and worst-case condition. After 1-4½ years, samples of the internal insulation were taken to investigate fungal growth, fungal species, moisture content and pH-value behind the insulation. Moreover, the development in pH-value of fresh cement-based adhesive mortars was investigated. The results showed that the fungal species, Aspergillus versicolor , was common in both floors and walls and indicate that the A. versicolor spores can survive the high pH-value (above 12), and then later germinate and grow when pH-value decreases and moisture content increases. Furthermore, the results showed that the pH-value decreased faster, when the surface/interface has access to air and that only a totally clean surface would prevent later fungal growth in the interface, if the pH and moisture conditions change in favour of fungal growth.

• Publication year

  2023

• Venue

  IV INTERNATIONAL SCIENTIFIC FORUM ON COMPUTER AND ENERGY SCIENCES (WFCES II 2022)

• Publication date

  Unknown publication date

• Fields of study

  Not labeled

• Identifiers
  DOI 10.1063/5.0173595
• External record

  Open on Semantic Scholar

• Source metadata

  Semantic Scholar

• No claims are published for this paper.

• No concepts are published for this paper.

• Hygrothermal performance of six insulation systems for internal retrofitting solid masonry walls

  2021cited by this paper
• Case study of fungal growth on newly cast concrete floors

  2021cited by this paper
• Laboratory-based investigation of the materials' water activity and pH relative to fungal growth in internally insulated solid masonry walls.

  2021cited by this paper
• Hygrothermal assessment of diffusion open insulation systems for interior retrofitting of solid masonry walls

  2020cited by this paper
• Internal insulation of solid masonry walls – field experiment with Phenolic foam and lime-cork based insulating plaster

  2020cited by this paper
• Energy savings and risk of mold growth in apartments renovated with internal insulation

  2019cited by this paper
• Micromycetes as colonizers of mineral building materials in historic monuments and museums.

  2019cited by this paper
• Moulds on cementitious building materials—problems, prevention and future perspectives

  2019cited by this paper
• A review of indoor microbial growth across building materials and sampling and analysis methods

  2014cited by this paper
• Microbial specialists in below-grade foundation walls in Scandinavia.

  2014cited by this paper
• Mold growth modeling of building structures using sensitivity classes of materials

  2010cited by this paper
• Food and indoor fungi

  2010influential reference
• The experimental investigation of concrete carbonation depth

  2006cited by this paper
• Airborne and soil microfungi as contaminants of stone in a hypogean cemetery

  2004cited by this paper

• Review of Deterioration Mechanisms and Durability Performance Mapping of Sustainable SCM Concrete in Wastewater Environments

  2026cites this paper
• Mould susceptibility of bio-based insulation materials in modern construction

  2026cites this paper