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Temperature Range for Painting Concrete Outside

Concrete is a tough, durable and versatile building material with one big advantage over some other building materials -- not needing to be painted to maintain its strength and integrity. It may be desirable to paint an exterior concrete surface, for aesthetic or safety purposes. When painting it, as with all exterior surfaces, you need to pay attention to the temperature.
  1. Temperature Range

    • The temperatures at which you can paint exterior concrete surfaces will vary according to the type of paint you use. Cold weather is the common enemy of all exterior painters. The general rule of thumb is to paint when the temperature is above 50 degrees Fahrenheit, but some manufacturers have paints that will cure at temperatures as low as 35 degrees Fahrenheit. You can paint exterior concrete with surface temperatures as high as 95 degrees.

    Weather Conditions

    • Temperature is only one consideration. Windy conditions can blow dirt and debris onto the painted surface. Direct sunlight may cause the paint to dry too fast, resulting in overlapping marks. Rain or high humidity can prevent the paint from drying properly.

    Dew Point

    • Different types of paints and different manufacturers provide different temperature ranges for applying paint to exterior concrete surfaces. You should paint concrete when the temperature is expected to remain within that range for at least 48 hours. If you expect significant changes between daytime and night time temperatures you should complete your painting job at least four hours before the temperatures are expected to reach the dew point. Most concrete paints require at least four hours to cure prior to moisture settling on the surface, according to the Sherwin-Williams website.

    Considerations

    • You should never paint freshly poured concrete. Concrete should be allowed to cure for at least 28 days before painting, according to the Concrete Network. The surface of the concrete should be dry, clean and free from oil, dirt and debris. Consider using paints that are specifically formulated for use on concrete. Concrete paints must allow moisture to pass through to the surface, or the moisture will accumulate between the concrete and the paint, resulting in peeling.