Thus it was the interplay of these economic, political, and social factors and forces that led to the scramble for Africa and the frenzied attempts by European commercial, military, and political agents to declare and establish a stake in different parts of the continent through inter-imperialist commercial competition, the declaration of exclusive claims to particular territories for trade, the imposition of tariffs against other European traders, and claims to exclusive control of ...
As general advice: RoofCoatingScam does not recommend regular roof cleaning just for the sake of improving the appearance of the roof. Foot traffic can damage roof tiles so we only recommend roof cleaning/de-mossing when it is absolutely necessary, ie when the moss is preventing water from draining off the roof.
Roof cleaning contractors who use sodium hypochlorite (chlorine bleach) mix it in high concentrations with other chemicals such as trisodium phosphate, also known as TSP. They spray it on the roof and wait for it to dry and then re-apply it several times as needed. Stains and moss or lichens that donât come off on the day of treatment may eventually come off with rain in the months to come.