Powder logistics hanging: chalk been subjected by the erosion of the coating produced is flushed into the area beneath it (such as brick), undermine the overall appearance (see chalking) phenomenon.
      Possible Cause: The reason is basically the same as above,
First, the use of low-grade, high pigment content of the paint.
Second, the exterior wall using interior wall paint.
Third, in the factory pre-coated metal siding eroded. Solution: The remaining powder compounds are removed as far as possible (see chalking).
      Detergent scrub with a stiff brush with the contaminated area and rinse thoroughly. If the pollution is serious, you may want to use pickling.
      No matter what method of treatment, if the affected wall color after drying, it is necessary to consider on which the coating quality latex paint. Erosion of aluminum in the coating quality exterior latex paint must be thoroughly cleaned before use (recommend using a power washer).

      Cracking / chipping: The dried film at least one layer split, eventually leading to complete destruction of the coating. Early on, there will be hairline cracks. Subsequently, the coating will peel off a thin sheet.
      Possible causes:
Second, the excessive dilution of the paint or paint too thin.
Third, the surface preparation is not good, especially painting bare wood when no primer.
Fourth, in cold or windy conditions so that a coating paint drying too fast.
      Solution:
First, the money still continue to repair the substrate is a viable method of cracking, brush to remove loose or has to be peeling paint flakes using a knife or wire, rounded corners, bottoming in bare spots and repainting.
Second, if the crack reached the surface of the substrate by scraping, sanding and / or heat gun to remove all of the coating, then the primer and repaint quality exterior latex paint.

      Contamination: the accumulation of dirt, dust particles and / or other debris on the paint film resembles mildew phenomenon.
      Possible causes:
First, air pollution, vehicle exhaust, fly ash accumulated on the walls of houses and horizontal borders.
Second, the use of low-quality paint, especially low-end satin or semi-gloss paint.
Third, the mud splashed on the wall.
      Workaround: Before wash primer and paint all the dirt on the surface.
      If you can not determine what the problem is dust or mold, you can do a simple field test (see mildew). With scrub brush and detergent to wash away the dirt, then rinse thoroughly with water hose connection.
      Especially dirty place to use a power washer to deal with. Although fouling can not be removed completely, high quality exterior latex paint can provide excellent stain resistance and washability.
      Moreover, high-gloss paints are more stain resistant than flat paint, flat paint because more and more holes accumulate dust. Similarly, the use of special anti-stick quality latex paint dust design