Chalk Run-Down probable causes - Chalk run-down occurs when paint erodes excessively onto another area below (a brick foundation, for example), ruining its appearance. The problem has a number of causes.First, the use of a lower-quality, highly pigmented paint or an interior paint can cause the paint to erode prematurely. Factory-finished metal siding can also erode to cause this problem.
Chalking solutions - First, remove as much of the chalk residue as possible by scrubbing any stained areas with a stiff brush and a detergent solution. Then, rinse the surface thoroughly. In cases of severe staining, an acid wash may be necessary. Either way, if the affected area dries to a different color, consider painting it with a quality latex paint. Eroding aluminum siding should be thoroughly cleaned (power washing recommended) before painting with a quality exterior latex paint.
Primers and exterior finishes - Priming is essential for better adhesion, sheen uniformity, mildew control and durability. Ask your Muralo dealer for the best Muralo exterior paint for your project, in the color and sheen of your choice.