A house exterior or interior that you want to paint while it is actively raining, though the actual painting surface is not being rained on.
You Want To Know:
If the presence of rain or general climactic conditions prevents you from painting or will adversely affect the quality of your paint job.
- Will it cause the paint to run?
- Will it take so long to dry as to affect its eventual cured state?
- Will it affect the paint's color or texture?
Exteriors and Interiors, Short Answer:
Yes, you can paint both the exterior and interior of your house when it rains. Exterior has limitations, detailed below.
Interior has no reasonable limitations. As long as the interior walls are dry and you do not expect them to get wet, you can paint. Keep in mind that windows left open during interior painting often experience sprinkles on the sill or the wall below the window.
Exteriors, Detailed Answer:
Many experts recommend against applying paint at the first sight of a rain cloud. But if you live in a rain-prone area, you would never get any work done if you retreated inside the moment the first drop fell.
Professional painters cannot afford to stop exterior painting every time a rain cloud comes onto the horizon. So how do they do it?
Painting season is not determined by terms such as "fall" or "winter," but by climactic conditions such as moisture and temperature.
As long as you are safely within those climactic boundaries, it can be considered painting season.
As you might expect, house exteriors are the most critical area to consider when precipitation has occurred or will occur.
Answer these four questions:
1. Is The Surface Visibly Wet Right Now?
Is the surface that I intend to paint currently wet?
Even a few drops count as wet.
2. If Not, When Was It Last Wet?
Even if a surface does not appear to be wet, it might have latent moisture that could affect your paint.
An exterior wall that was rained on may require 4 hours of drying time in direct sunlight and 72+ F temperature in order to be fully dry for painting. Ideally, you would want to wait a full work day for the surface to dry.
Even if the flat surfaces have dried, other areas might not be:
- Sections that are hidden from the sun.
- Trim and molding.
- Hairline cracks in the siding
- Nail holes
A common scenario: You touch the wall and it feels dry. But when you run your brush across a nail hole, this releases built-up water. If you do not catch this right away, the water drips down your newly painted surface, creating light streaks. The only cure for this is an additional coat of paint.
3. Is the Temperature Right?
Is the outside temperature below the minimum recommendation as specified on the paint can? Temperature and moisture work in conjunction with each other. The lower the temperature, the longer it will take for your exterior surface to dry.
4. Will Temperatures Drop Below Minimums?
Will the temperature drop below the minimum within 8-10 hours of paint application?
Be reasonable, though. Some paints can be applied in temperatures as low as 34 F. If you are painting at exactly 34 F at 10:00 am, and you expect it to hit freezing at 6:00 pm, you are unreasonably pushing the envelope. Give yourself a buffer zone.