Whoa, Put the Paintbrush Down! It’s a beautiful sunny day without a cloud in the sky. You’re feeling motivated and think, “What a perfect day to paint the exterior of my house!” But before you break out the paint cans and ladders, ask yourself – is it too hot to paint outside today?
The temperature outside can significantly impact the outcome of an exterior paint job. When it’s too hot, you may end up with paint that blisters, bubbles, cracks, or
peels right off the surface. Yikes! So what is the ideal temperature range for exterior painting? Let’s break it down.
The Science Behind Paint and Heat
The paint contains surfactants that allow it to coat and properly adhere to exterior surfaces. Most paints also contain additives designed to facilitate proper drying and curing.
The chemical reactions can go haywire when these paints are exposed to excessive heat and sunlight. The paint dries too rapidly, preventing proper adhesion to the surface. This leads to failure of the paint coating down the road.
Latex vs. Oil-Based Paints
Latex (water-based) paints should be applied when surface and air temperatures are between 50°F and 85°F. Oil-based paints have a wider temperature range – between 35°F and 120°F.
Latex paints are more sensitive to heat because of their water content. The water evaporates quickly in high heat, thinning the paint and interfering with proper curing. The pigments can’t bind correctly to the surface when the water content is off.
Oil-based paints are more heat-resistant, but even they have their limits. At extremely high temperatures over 120°F, oil-based paints also risk improper curing and adhesion failures.
Surface Temperature vs. Air Temperature
When determining whether it’s too hot to paint outside, measuring the surface temperature is crucial rather than relying solely on the air temperature.
Sun-exposed surfaces can be significantly hotter than the surrounding air, sometimes reaching temperatures 10-25 degrees higher. Use a surface thermometer to gauge the surface temperature accurately before starting your project.
At What Temperature Is it Too Hot to Paint?
As a general rule of thumb, if the surface temperature exceeds 90°F, it’s best to hold off on exterior painting. Here are some specific temperature cut-offs to keep in mind:
- Latex paints: Surface and air temperature shouldn’t exceed 85°F.
- Oil-based paints: Surface temperature shouldn’t exceed 120°F.
- All paints: If you can’t touch the surface for more than 5 seconds, it’s too hot!
Dangers of Painting in Extreme Heat
Attempting to paint in sweltering temperatures can jeopardize the success of your paint job. Here are some common issues that arise:
- Bubbling, cracking, blistering, peeling, and chipping of paint
- Paint dripping and running down the surface
- Uneven glossiness or sheen of the dried paint
- Lap marks from paint drying too fast
- Paint getting tacky and sticking to rollers and brushes
- Paint pulling off the surface as it dries
Yikes – it’s a hot mess!
No one wants to deal with these frustrating problems after spending time and money on painting.
Play It Cool – Tips to Paint in Warm Weather
Does this mean you can’t paint at all in the summer? Not necessarily. With smart preparation and planning, you can still paint in warm weather:
- Paint in the cooler morning hours – focus on the shady sides of the home before the sun gets too intense.
- Use high-quality paint – invest in paints designed for hotter climates.
- Watch the weather – avoid painting on sweltering & humid days or before rain storms.
- Work in the shade – move scaffolding or ladders as needed to stay in the shade.
- Use additives – add paint extenders to increase open time in the heat.
- Keep paint cool – store cans in the shade or in a bucket of ice water.
When In Doubt, Call the Painting Pros!
For best results in warmer weather, consider hiring professional exterior house painters. Experienced painters are trained to monitor conditions and adjust their process to account for temperature, humidity, and sunlight exposure throughout the paint job.
Pro painters have the skills to properly prep surfaces, apply paints, and use additives to maximize quality. They also have commercial-grade sprayers and other equipment to optimize efficiency.
Don’t waste time and money on a botched DIY paint job; leave it to the pros. Request a free estimate from HBP, the trusted exterior painting expert.
