Condensation is what we commonly know as humidity. It is warm air that, due to poor ventilation, a very closed place, or very humid environments without air conditioning, causes this type of humidity. It occurs in any home because they cause by everyday actions. For example, bathrooms, kitchens, or laundry rooms are places that can appear, giving the appearance of wet-looking spots on walls

What causes condensation spots on walls?

Condensation occurs when the air is loaded with moisture, for example, a very cold room with a radiator generates a hot “cloud” that if not dissipated can form spots. This occurs because of no good ventilation and will condense, then you can expect drops produced inside the house that will condense on walls

Condensation occurs in places in the house where the air tends to be still, such as in the corner of a room or behind furniture, for example.

What does condensation on walls look like?

prevent mold in bathroom ceilings

One of the most common signs of condensation is black mold.

Water pooling on windows is a common symptom of condensation in homes.

The plaster will begin to deteriorate if the condensation problem is not treated quickly. The walls will also appear damp.

How do you stop condensation on walls?

Moisture problems can be varied but also can be easily pinpointed, e.g. rain seepage on walls and ceilings, moisture on the floor, condensation on cold surfaces, or a mixture of all. Investigate the cause to find a solution to the problem.

Damp from capillary action

If there are damp spots, or bubbles in the paint and it crumbles the paint or there is dust on the floor and surfaces. The answer is rising damp. This occurs when there is no insulation or initial sealant layer between the masonry and the paint, poor ventilation, or poor drainage.


  • Improve the drainage of the house. Make sure the surrounding ground slopes away from the building. Check the ventilation of the house and the floor, so that there is sufficient space for ventilation.
  • Install a damp-proof coating. This work is best left to professionals.

Condensation on the walls

A simple test will determine if it is a damp stain on the wall or condensation. Put a piece of aluminum foil on the drywall in the affected area and leave it stuck for 24 hours. If after that time the surface has water droplets, there is warm or humidity-laden air inside the house, this is due to poor ventilation.


  • Install exhaust fans to remove the hot air and keep the room at a stable and comfortable temperature.
  • Check the shoring systems in your bathroom, kitchen, and laundry room to expel the humid air that accumulates in these rooms.
  • Do not use moisture-producing portable gas heaters to heat cold, damp rooms.

Moisture Stains

Destroyed wall by moisture

They are usually caused by rainwater penetrating and settling on windows and doors through cracks in the roof or poorly fitted windows.


  • Keep exterior walls in good condition, including grouting and paint.
  • Seal gaps around door and window frames.
  • Clear or cut drip grooves under sills


They are quite common, is normal to experience them if the structure of the roof expires, gets damaged and the repairs are not effective, etc. This causes leaks and therefore damp stains.

These are easy to detect as they are found in the roof or in sections of the wall that coincide with the exterior plumbing. This type of dampness is not only attributed to leaks but also to leaks from existing pipes in walls or ceilings.


  • Repair a faulty roof.
  • Repair leaky pipes.

Waterproofing, good ventilation, checking the walls for signs of moisture, and periodically cleaning the corners of furniture, are steps from the largest to the smallest to avoid condensation spots on walls, in any room of a house. Don’t let dampness get the better of you because it has structural consequences and can cause periodic allergies in both children and adults.

What causes condensation spots on walls was last modified: March 17th, 2023 by Vanessa Gallanti
Your opinion matters, leave a comment
Inline Feedbacks
View all comments