Low Temperature Exterior Painting

Did you know that the US collectively use 1.57 billion gallons of paint each year?

Painting the exterior of your home is dreaded by many and for the right reasons. It is a painstaking task that takes days, if not weeks, of planning and preparations to get it painted. In many cases, you may have to hire a contractor for the task.

But not every season is apt for exterior painting. For it to last its life expectancy of 5-10 years, you may have to paint at the right weather and temperature.

We bring you a professional exterior painting guide with the right temperature, climate, and humidity, expert painting tips, and many more.

Appropriate Weather for Low Temperature Exterior Painting

The ideal weather for painting is the dry weather, particularly early summer and early fall, without any significant temperature fluctuations between day and night. The steady temperature helps the paint to go on smoothly and also dry quickly.

If you have a sudden drop in temperatures at night, the paint will not have time to react and cure properly. Also, the weather should remain the same for a few days before and after the paint job.

The same is the case for rainy days. Do not plan exterior painting of your office or home if it has rained in the last few days or if you are anticipating rain.

Outdoor Temperature Range for Exterior Paint

The temperature range for exterior painting depends on the type of paint: oil-based or water-based paint. As a rule of thumb, for oil-based paint, the temperatures should be between 40°- 90° F, and for latex paint, it should be between 50- 85° F.

Ideally, considering everything, the best paint for the exterior is latex, with temperatures ranging between 60-85° F. with little to no wind. As for humidity, it should be within 40%-70%.

Too high or too low temperatures cause the paint to crack and peel off within a few days.

Exterior Painting in Cold Weather

Temperature is one of the factors that play a vital role in the paint bonding to the surface. And as such, winter may actually be a good time to paint your house since the days are dry with low humidity.

As for the paint reacting with the surface, go for water-resistant paints formulated for cold weather. They can be used in temperatures as low as 35° F. It’s not the daytime temperature that matters but the night time, which means your overnight low should be 35° F or higher.

How To: Paint in Cold Weather

The dry air quality and the cold weather make winter an ideal time for your painting projects, provided that you have latex paint designed for use in temperatures as low as 35° F. If not, go for oil-based paints since they do not freeze in lower temperatures.

Here are the steps you need to take to make sure the paint goes on smoothly:

• Make sure that you have self-priming paint. If not, first go over the surface with a bonding primer and then the paint.
• Pay attention to the surface temperatures. Wait until it has reached the minimum temperature. The air temperature may not be the same as that of the surface you are painting on.
• Also, keep an eye on the wind speed and direction. They can directly impact the temperature of the substrate.
• Ensure that the paint and the tools are suitable for cold temperatures.

Latex Paints not Formulated for Low Temperature Exterior Painting

In case you haven’t been able to procure paints with lower curing temperatures, you can continue with your painting. Here are a few additional steps you would have to ensure a smooth process:

• The surface temperature should be 50°F. If not, you can use a hairdryer or heat gun to heat the area.
• If the air temperature is not yet 50 degrees F, you may want to build your bubble similar to a greenhouse.
• Build a 2×4 structure and cover it with a sheet of plastic. Run a space heater inside to warm the area. Paint inside the heated area and leave the heater running for a few more hours. Keep in mind that you need to maintain the temperature.
• Add appropriate additives to prevent it from getting thick in the cold.

Low Temperature Exterior Painting Tips For Your Home

Here are a few tips to get the best out of your exterior paint during the cold weather.

• Paints can undergo multiple freeze-thaw cycles and be reusable on the condition that it isn’t lumpy.
• Lower the temperature and longer is the drying time between coats.
• Timing is the key. Work in the mid-day between 10 am to 2 pm to better utilize the sunlight.
• Track the sun around the house and restrict it to the area that is receiving direct sunlight.
• Allow for more drying time than that of summer.

Never Paint Your Home in These 3 Weather Conditions

Depending on your paint, the ideal painting conditions can range between 35-85° F. But then again, the paints should either be acrylic or latex paints formulated for cold weather. Other than those, here are some weather conditions during which you should never paint your house.

• Freezing conditions and lower temperatures below 35°F Do not repaint before the painted area is dry.
• Do not paint on wet substrates. Keep an eye out for the moisture content before painting.
• Too hot isn’t ideal either. Your paint would be dry before it cures, leading to cracks. So, avoid painting in the sun.

Influence of Temperature and Humidity In Low Temperature Exterior Painting

High humid conditions can lead to surfactant leaching, which is the white or brown discoloration you see on the top of the paint. It also compromises its protective properties.

If painting on a wood surface, the wood absorbs the moisture content from the air, affecting the adhesion and increasing the drying time.

Similarly, lower temperatures also affect the drying since the paint thickens in cold weather, making it difficult to apply. Contrarily in high temperatures, the paint dries quickly, leaving bumps, blisters, cracking, and discoloration.

Conclusion

Painting your house is a huge undertaking that needs proper planning, starting with the weather conditions. Early summer and early fall are the ideal seasons to paint your house.

But, unlike the common misconception, exterior painting can be done in winter, too, provided you use water-based latex paint formulated for cold weather.

Make sure you keep an eye on the weather forecast for rains or cold fluctuations. They can affect the curing process and leads to cracks, blisters, and peeling paint.