When bricks are burned at high temperature, all organic material is incinerated
and the bricks become inorganic. Bricks often have stuck –which
lead to the bricks gaining organic qualities.
The dirt on the brick surface binds damp and in the damp there is nutrition that furthers affection growth of lichen. The affections are serious since the fungus threads –the mycelia- binds strongly to the bricks and since the algae are protected within the lichen.
Lichen establish themselves fast and they are considered as the most difficult affection growth to treat. It requires that all of the bricks pores are sterilized and that all remainders of old lichen –and its spores- totally removed.
The surface becomes disinfected.