There’s nothing like a bit of humidity to make painting work a challenge. For painters, high humidity can cause issues with the drying and curing times of the materials you use. This isn’t an issue if you’re working indoors in a climate-controlled environment, but it can be a major pain in most other situations. If you aren’t careful, all your hard work could be wasted on a humid day.

This doesn’t mean that you have to shut everything down once humidity starts rising, of course. While extreme humidity can cause work delays in some cases, it’s often possible to work on humid days without having the humidity ruin your applications.

Why Humidity Affects Paint and Adhesives

Most people know that humidity can ruin a paint job. There are even warnings on the cans of most paints and adhesives letting you know that high humidity will give you problems. However, it’s possible that your crew (and that could possibly include  even you) isn’t aware of just why humidity’s a problem. As with most things, understanding a problem is the first step toward overcoming it.

Paints and adhesives typically contain solvents in addition to the water or oil that acts as a base. This is what cures your paint or adhesive. Under normal humidity, the water or oil in the paint evaporates at about the same rate as the solvent; this gives you the nice smooth finish you want in your finished product.

High humidity affects the evaporation rate, resulting in curing going faster than evaporation. This leaves water or oil behind in your finished product, which at best causes early flaking and at worst creates an awful mess.

Choosing the Right Materials

Some materials handle high-humidity application better than others. Choosing a faster-drying paint or fast-set adhesive makes a big difference when the humidity is high since it’s designed to dry out quicker than the materials you’d normally use.

This means you have to be more careful with your application, of course; fast-dry paints and other materials get tacky much quicker, so you don’t have nearly as much time for correction. Spray application and thin coats can save you a lot of problems here, since there’s less chance of accidentally introducing unwanted texture during application.

Get an Early Start

During the summer, humidity often increases as temperatures rise. This means the humidity is typically lower during the early part of the day and higher in the afternoon. If you’ve got work to finish, take advantage of this by doing as much of your onsite work as possible during the morning hours while the humidity is lower. Reserve the afternoon for indoor work in climate-controlled locations and things like paperwork, job bids and supply runs.

Be sure to keep morning dew in consideration, however. Starting too early might mean that you’re working with damp materials, which just add more water to the mix and take you right back to the drying problems you have when humidity is high. Worse yet, if things are too wet then you could end up with bubbles or materials that your paint or adhesives just won’t bond to.

Improve Air Flow

If your situation allows for it, you can speed up drying by using fans to increase air flow over your drying paint. While this isn’t practical in all situations, there are some scenarios where you can add to your airflow in humid environments. The increased airflow speeds up the evaporation process, helping it to catch up with curing and ensuring that excess moisture isn’t left in your paint.

Watch the Humidity

In the end, one of the best ways to avoid issues with high humidity is to keep an eye on the humidity and avoid working in environments that are too humid. Humidity up to 70 percent is fine to work in and environments with 80 to 85 percent humidity are usually fine with precautions.

If the humidity goes above 85 percent, though, you’re going to have a hard time, no matter what you do. To avoid potentially serious complications, pack things in and come back in the morning if the humidity hits that point.

Which month is worst for high humidity in your area? How do you compensate for it?

PaintTalk.com