For biodeterioration and biodegradation of stone the most important microbial groups are algae & blue-green bacteria (cyanobacteria), autotrophic and heterotrophic bacteria and filamentous fungi.

A number of bacteria, actinomycetes, algae, fungi, blue-green bacteria (cyanobacteria) and lichens can cause decay of stone in our buildings for example Slime moulds, protozoa, nematodes and rotifers, arthropods (e.g., mites), small animals (e.g., slugs) and plants.
These can cause mineral dissolution, formation of patina, chemical, physical and mechanical degradation of stone surfaces by producing a range of organic and inorganic acids. Microbial growths on stone surfaces can cause aesthetic biodeterioration, discolouration and soiling,
Most buildings surveyed by EBS staff have some form of microbial growth on the stone finishes, for example Epilithic i.e. growth on surface, Chasmoendolithic i.e. growth within cracks and Euendolithic i.e. growth within the stone for example boring attack.

All types of stone building materials for example: Limestone, Sandstone, Granitic, Marble, Quartzite are susceptible to micorbial attack.



The solution
EBS undertakes ecological stone surface investigations to determine the type, extent and distribution of microbial infestation and ecological succession. Based on the information gained from EBS surveys, non-destructive sampling, assessment and laboratory analysis, recommendations for conservation cleaning and repairs are provided in order to preserve original features and finishes.

Some targeted use of chemicals, biocides, pesticides and other control treatments may be needed combined with environmental monitoring. Beware of someone recommending complete biocide treatments of an entire stone façade in a building, as this is unnecessary and does not address underlying causes.

EBS environmental approach based on prevention and maintenance provides cost-effective environmentally sustainable long term solutions.