How Summer Temperatures Affect Paint

calander Jun 17 , 2020 user-icon Nash Painting

Summer can be somewhat of a double-edged sword for home improvement projects. On the one hand, most Americans have some more free time to get things done during this time of year. But on the other hand, the summer heat can get in the way of these efforts in more ways than one, especially when it comes to exterior home painting. Not only is it potentially dangerous to exert too much energy in the hot sun -- high temperatures can negatively affect the paint job itself. So, before you get started or schedule a contract with local exterior painting services this season, let’s explore how summer temperatures affect paint.

How Heat Affects Paint

In Nashville, TN, the average summer temperatures land between 65 and 90 degrees Fahrenheit. We all know the difference between a 65-degree and 90-degree day because we can feel the heat on our skin. While paint can’t “feel” the heat like we do, it still reacts to it. Heat, after all, is simply a transfer of kinetic energy, and varying amounts of energy can affect physical and chemical properties in different ways. In other words, a certain level of heat (or lack thereof) can alter the way paint is meant to function -- more specifically, it can cause it to dry at a faster rate than normal, resulting in cracking, peeling, and improper binding overall.

For these reasons, paint manufacturers thoroughly test their products in a wide range of conditions. Then, they label their products with their application recommendations. Generally speaking, most latex and oil paints should be applied between 50 and 85 degrees Fahrenheit, meaning an average summer day in Nashville is usually fair game. Of course, an individual paint product will have more specific instructions, which may be more or less lenient regarding optimal heat.

Additionally, it’s worth noting that a thermometer or weather app might not be the best indicator of a surface’s actual temperature. This is because ambient temperatures (i.e. the temperature in the air) and surface temperatures can differ significantly. For instance, a surface may be several degrees warmer than the air if the sun is blaring on it directly. The color of a surface/paint makes a difference, too -- lighter surfaces reflect light and heat and darker ones absorb it. This is why many professionals will use a dual laser infrared thermometer to check the surface temperature before painting a house exterior, especially during the summer.

Humidity Plays a Role, Too

While heat is a major factor in the proper application and drying of paint, humidity cannot be ignored. And as it turns out, heat and humidity are directly related -- as temperatures rise, so does relative humidity, because warm air can contain more moisture than cool air. While heat on its own can cause paint to dry too quickly, high humidity interferes with the paint’s rate of evaporation.

Paint is composed of solvents and a base (water or oil), both of which should evaporate at roughly the same rate in order for the paint to properly cure. When relative humidity levels exceed about 70%, the solvent cures faster than the water or oil can evaporate, leading to premature flaking and a poor overall finish. Nashville painters must always keep this factor in mind when painting outdoors in the summer, as regional humidity levels can get upwards of 85% on certain summer days.

Looking to Paint Your Home this Summer?

While it’s good to know how heat and humidity can get in the way of a good paint job, don’t be afraid to invest in some home improvement this summer. Rather, pay attention to the forecast and work with an experienced contractor that takes these factors into account each and every day. If things are heating up or getting too humid, you may have to put your exterior painting on hold momentarily. But when it comes to home interior painting, this can be done all year-round. Whatever the case, the experts at Nash Painting can help you make the right call and get the job done when the time is right. To learn more about us, our services, and our values, call us at 615-829-6858 today!