Exterior painting is a significant task, and it stands out as one of the most crucial responsibilities for anyone looking to enhance their home or any building. Paint serves as a protective barrier, enhancing the exterior’s appearance while safeguarding it against unexpected challenges. One important aspect that often goes overlooked when it comes to painting is the temperature. The adhesion and drying process of paint can be affected by factors such as relative humidity, temperature, and wind. Let’s take a moment to explore the ideal temperature for painting exteriors and the reasons why it’s so important.
The Importance of Temperature in Painting
Paint can experience different temperatures while still being in its liquid state. In fact, temperature plays a significant role in drying time, smoothness, and adhesion of the paint to the surface. A problem with low temperatures is that the paint remains wet, sticky, and does not set correctly to become appreciably hard in a relatively short period. However, if the temperature is too high, the paint dries very fast and forms a skin: a bad finish is achieved with poor hiding ability and the paint may crack.
Ideal Temperature Range
The majority of paint manufacturers suggest preferred temperature for application of paint to be around 50°F (10°C) to 85°F (29°C).
Here is the rationale for this range:
1. 50°F to 85°F (10°C to 29°C):
Slow to Moderate Baking: This ensures the paint dries at an equal and uniform rate so that there is a good finish on the surface. It also enables proper setting of the paint, and this usually results in the formation of a long-lasting and tough film or layer.
Avoiding Cracks or Bubbles: If the formulated paint is too cold it will take time for the moisture in the paint to evaporate, and this will lead to the formation of bubbles or cracks. On the other hand, high temperatures may result in early drying of the paint, thus resulting in the formation of cracks.
Protection: Depending on the climate, the paint will provide good protection in terms of moisture accumulation when applied in this temperature range.
Painting in Cold Weather
If it is necessary to paint at low temperatures, here are some suggestions:
Cold Temperature Paint: Use paint that is intended for application in cold areas. Instead of using one pure formulation, these paints may be used with additives that improve its capability at chillier temperatures.
Avoid Painting Below 35°F (2°C): As a rule of thumb, it is recommended that one should not paint during extremely cold conditions below 35°F (2°C) as it may lead to poor adhesion of the paint and it may peel off.
Check Humidity: One must ensure that the humidity is low, especially when painting in cold weather; the drying time will be longer because the air is moist. It is recommended to choose a day with minimal humidity as paint dries best with low humidity.
Warm the Surface: Individuals may use heat lamps to warm the surface. Using this method of application will ensure better adhesion.
Painting in Hot Weather
Painting is very different in high temperatures and it has its own trials and tribulations, which are as follows:
Heart of the Summer: Paint in the morning or late evening; do not paint during the midday when the sun is at its strongest. The temperature when painting should not go above 85° Fahrenheit, especially not if there is high humidity as well. The high temperatures can interfere with the paint’s drying process and may result in an improper drying, thus affecting the quality of its finish.
Morning or Evening Paint Jobs: If you are painting during the day, then paint early in the morning or late in the evening when it is cooler.
Select the Right Paint: Use paints that are heat resistant and that cover all surfaces uniformly.
Protect the Surface: Painting should be done under shades or tarpaulins to avoid the heat from the direct sun.
Humidity and Dew Point
Humidity and dew point are also other important things that have to be taken into consideration when painting exteriors.
Humidity: Humidity is somewhat detrimental to the drying of paint, because when the weather is humid, the paint will take much longer to dry because moisture in the air affects the paint. It is preferable to paint when the humidity level is under 70%.
Dew Point: This refers to the temperature of the air at which point it forms dew. The problem of painting specifically when the temperature of the room is high but close to the dew point is that it can lead to a number of issues such as streaking or poor adhesion of the paint. That is why it is advisable to paint when the temperature increases to 5°F (3°C) or more, compared with the dew point.
Checking Weather Forecasts
When embarking on your exterior painting project, it’s a good idea to look for a few days of stable, relatively low temperatures in the area
