Through a demonstration experiment at the Nakijin Village Central Community Center, measures focusing on moisture content in salt-damaged concrete were examined. It was confirmed that the moisture content did not increase at a roof angle of about 5°. For a cover thickness of 30 mm or more, the moisture content migrated within threshold to prevent rebar corrosion (less than 4 kg/m³ chloride ion content and less than 3.5% moisture content). In addition, it was also confirmed that the effect of the impregnation material in inhibiting water penetration was maintained even after algal blooms.