High Humidity: To Paint or Not to Paint

Humidity can cause significant challenges for your painting projects. Outdoor projects or indoor projects where you don’t have a climate-controlled environment can experience difficulty when your paint won’t dry in a timely fashion. Gravity will win the battle and you will watch your newly applied coat running and forming into ugly drips. However, when the humidity climbs, it doesn’t mean you have to throw in the towel just yet.

Understanding the problem like professional painters is the first step. High humidity interferes with the evaporation rates of the various paint ingredients. Paint contains solvents that helps cure the paint. Paint also made up of a base that is usually water or oil based. In a high humidity environment, the solvent and the water or oil base will evaporate at different rates leaving behind a mess instead of that nice smooth finish you were expecting. Under normal humidity conditions these ingredients are designed to evaporate at the same rate.

You will need to keep a watchful eye on the weather forecast and plan ahead for those humid days. Tracking the sunshine, clouds, temperature, and rainfall isn’t enough. Humidity matters.

First, start by using products that are specifically designed for high humidity conditions. These products will usually be labelled as quick drying. These products are best applied by sprayers and in thinner coats.

Secondly, planning to have the right equipment on site is important as well. Using fans to increase the air flow across your project will help to speed up the evaporation rate. Increasing the evaporation rate of the base components to closely match the curing rate of the solvents will help to eliminate that extra moisture.

Next, plan your day. You will need to sandwich your application time in-between the dew of the early morning and the high humidity that usually comes with the higher temperatures of the afternoon. These down times can be used efficiently by prepping other surfaces, masking the next area to be coated or spending more quality time with family.

Keep watch on the forecast humidity levels with an app on your mobile device. Most weather apps will provide humidity levels in a percentage format. Humidity levels up to 70 percent shouldn’t cause you any grief. Even as high as 85 percent could be okay if you plan properly with the tips we suggest here. Any day over 85 percent humidity and you should skip the stress and plan a well-deserved day at the beach.