Internal paint blisters or salts appear after rain.
Use the site evidence to agree a project-specific method with the responsible engineer, concrete producer, manufacturer or specialist applicator.
Internal paint blisters or salts appear after rain.
Map rain exposure, cracks, parapets, façade joints and service penetrations.
Water may enter high above the visible patch and travel behind finishes.
Repair cracks and façade details, then choose a breathable or barrier system appropriate to substrate and exposure.
Prepare sound surfaces and treat joints and window interfaces before broad coating.
Use a staged spray test and moisture monitoring to confirm the source is controlled.
Do not seal a damp interior face before tracing external entry and drying path.
References inform the topic; they do not endorse a specific product for this project.