Yellow, oily drops bleeding through your walls or forming on your ceiling are unsightly and have several causes. These yellow drops can form in any room of the home but are most likely to be found in bathrooms and basements. When you stop the drops, act fast to avoid permanent stains in your home.
There are several different sources of yellow drops on your ceiling, walls, or doors. Finding the source of the stains will help you know how to eliminate the drops and keep your walls and ceiling from staining.
If you or someone in your household smokes, the tar from the cigarettes can collect on the walls and ceiling, react with condensation, and create yellow drops. Even in the smoker lived in your house a long time ago, there is still a chance that the tar and chemicals from the cigarettes still exist on your walls. If you think that smoking is the cause of your yellow stains, clean them quickly. When they first form, these yellow, oily drops will be easy to wipe away with soap and water or a DIY cleaner of your choice. The longer you wait to wipe away yellow stains caused by smoking, the harder they will be to fully remove.
Did your bedroom or bathroom used to be covered in wallpaper? If so, the wallpaper removal process may be your problem. If your wallpaper paste wasn't removed completely before the walls were painted, you could be seeing old wallpaper paste leak through the paint. Especially in a bathroom or a humid climate, if the paste is there, you're likely to see yellow spots form. You could even see these spots form on wallpaper that is currently on your walls.
To remove these spots use a cleaning method that is safe for the type of wall finish you have. Then, treat the larger issue at play: ventilation. Poor ventilation can be a major culprit when it comes to these yellow spots. You may need to open a window or install a fan.
Paint experts are well acquainted with leaching, and you should be too. Surfactant leaching happens with latex-based paints. Surfactants are a substance that sits on the surface of latex paint and under certain circumstances, can cause yellow leaching spots.
A few conditions that cause these drops to form are cool and damp conditions, cool temperatures while the paint is drying, and rain or steam. When possible, introduce a good ventilation system to your bathroom. When you remove the yellow drops, it may take a few scrubs to fully remove the yellow residue. Wash the wall once and then let then wait a day or two and wash it again.
Pro tip: to prevent leaching in the first place, let the paint dry fully before running the shower in a bathroom. To prevent leaching in the bedroom, use a dehumidifier when painting in a humid climate.
Burning candles in the bedroom, using certain hair products in the bathroom or even scented wall plugins can leave chemical residue on your walls, ceiling, or door. When the room gets humid and that water has nowhere to go, the water sits on the wall and pulls those chemicals forward—and as it dries, it leaves those yellow drops. Aside from adding better ventilation to your rooms, take a good look at the products you are using every day to see if some of those chemicals could be the culprit.
When the drops form in your bathroom or bedroom, they are easy to see and catch. But often these drops form in crawl spaces and basement corners and go unnoticed. If you see these yellow marks forming upstairs, it's a good idea to take a minute to check the basement for other marks. Look in places that are cool and damp, that have paint on the walls, or have previously been wallpapered.
It's also a good idea to check these areas for mold.