Is Exterior Paint Affected by Rain?

Cured exterior paint is not affected by rain; it is made to repel water. The risk lies in the first hours and days after application: rain that falls before the paint has dried makes it run and leaves stains and differences in shade.

Before and after rain

• Before painting: the facade must be dry; after rain you wait until the wall has dried out.
• During painting: if rain starts, work stops; there is no point trying to cover the painted area.
• After painting: the paint needs a dry spell to cure; how long is stated in the product data sheet.

What happens if rain hits before it dries?

The paint runs, leaving streaks and differences in sheen; in bad cases it blisters. The fix is to repaint the affected facade from corner to corner once the surface is completely dry.

Dew and mist count as rain too

Dew that settles in the evening affects paint applied late in the day just as rain does. That is why in damp seasons painting stops a few hours before sunset.

How is the weather followed?

You look at the forecast for the following days, not just the day itself. Waiting a day on a scaffolded facade is cheaper than repainting a spoiled one.

Why does rain stain an old painted facade?

Paint that has lost its water repellency absorbs water and darkens as it gets wet; this shows it is time to repaint. Erdağ Yapı plans application days by the forecast; details are on our exterior facade paint page.