Novice painters often welcome hot weather, assuming it makes the paint dry faster . . . which it does. But what eludes them is the fact that there are dangers in having paint dry too fast. Even in Nashville, where the air stays moist when it’s hot, those dangers are still worth considering. Here are some pros and cons of painting in hot weather, especially with residential painting.
- Joint compound, spackle, and primer dry more quickly, requiring less time to prep before painting.
- Paint dries quickly, so you can apply a 2nd and even 3rd coat (if needed) the same day.
- The paint smell disburses more quickly, especially outside. Note the importance of using fans inside, whatever the weather.
- The can of paint, itself, is warmer and the paint slightly thinner, so it flows on more easily.
- If the paint dries too quickly, it won’t set properly. It will have the same effect as painting over unprimed dry wood (which absorbs water from the paint).
- If paint dries too fast while you’re still painting, the part you just painted may not blend properly with its neighboring section. Instead, it will overlap, looking like a top coat, instead of the same coat, and leaving a line where they cross over.
- As you use and set aside brushes and rollers, they will dry out and be more difficult to clean afterward.
- A quick evaporation means a stronger effect on the painter, as the chemicals vaporize.
Paint Curing Process
Paint needs to “set,” which requires a certain amount of liquid to stay with the paint while it dries. The pigment and resin particles in paint need to come together to fuse into a strong covering. As water evaporates, those particles begin to move together. If the temperature is too hot, such that water evaporates too fast, the particles will not have come together closely enough to fuse properly and the paint will eventually crack. For this reason, most professional painters will not paint when the temperature is above 90 degrees.
Health Effects of Painting in Hot Weather
Inside a room on a hot day, paint fumes collect quickly near the ceiling. If a painter is on a ladder, they can’t help breathing those concentrated fumes, which can make the painter spacey and clumsy. They may drop a brush, knock over the paint can, paint in the wrong place, drip paint and not catch it, lean against fresh paint, or just forget to paint a section. All of these things are easy to do when high. And the fumes are toxic. (See link below.)
Techniques for Painting in Hot Weather
If there is no other chance to paint than during hot weather, there are some techniques good painters use to lessen potential problems. For exterior painting they will start as early in the day as possible, after any dew has evaporated. As the sun rises higher, they will paint the shady parts of the house, following the shade around until the house is finished. During the hottest time of day they stop painting, until it cools down a little.
For interior painting they will paint from top to bottom, covering the ceiling and tops of the walls first, while the day is still cool. On a hot day that is also humid, they will use a greater number of fans than usual, so the humidity cools the room. Fans are directed away from freshly painted areas. Fans also help to disburse the fumes, keeping the painter’s focus clear and steady, and resulting in a better quality job.
The Choice Is Yours
It’s up to you and where you live as to whether you paint in hot weather or not. It would be interesting, though, for other readers to know what your experiences have been. If you have your own tips for painting in hot weather, or better yet, a story, be sure to leave a comment in the box below or connect with us on our Facebook page. We want to hear from you!