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Condensation on Walls: Why Does My House Have Wet Walls?

Published on Saturday September 30, 2023

Your house shouldn’t have wet walls. Sure, we’ve all seen condensation in our bathroom after a long, hot bath or shower — but those droplets should dry by the time you’re done using the hair dryer. There shouldn’t be any marks or mold left behind. And there certainly shouldn’t be any damp patches on walls after heavy rains.


Signs of Wet Walls

If the walls of your home are consistently wet, sweating, damp or slick, you may have a moisture problem. Here are a few common signs that you have too much moisture in your home:

  • Peeling paint or wallpaper
  • Watermarks or staining
  • Wet spots on the wall or ceiling after rain
  • Water running down indoor walls
  • Walls that feel damp to the touch
  • Visible mold
  • A musty, stale odor

What Causes Wet Walls?

Usually, the source can be traced to either trapped moisture or unwanted infiltration. Condensation, leaks, and poor drainage are the usual suspects behind moisture troubles in homes.

Damp can cause wet walls in a home


Condensation occurs when hot, moist air hits cold, dry air. This meeting causes water droplets to form on cold surfaces like walls. This kind of moisture is what you’ll find on the bathroom walls after a super-hot shower.

Condensation on internal walls is more common in bathrooms and kitchens, where steam is produced by bathing or cooking, but it can be found in any room, including your bedroom or living room. A large temperature difference between the air outside and the air inside your home encourages condensation on surfaces like walls and windows on the inside of your house.

This can encourage mold growth and drywall stains. Fortunately, there are relatively easy solutions to condensation issues and interior walls sweating, such as dehumidifiers. If that doesn’t solve the problem, your roof may need ventilation improvements.

Plumbing Problems and Leaks

Leaky fixtures, dripping faucets, or slowly seeping sinks are common causes of leaks and wet walls. Beyond these, water-wielding appliances like washing machines and dishwashers can also cause leaks. The intricate network of plumbing pipes and connections is susceptible to wear and tear, leading to potential leaks anywhere in your home.

However, it’s not just about inconvenience; leaks can become costly water damage if left unattended. Drips can seep into floors and walls, causing structural issues and encouraging mold growth. Regular inspections and maintenance of plumbing systems can help catch potential leaks before they become major headaches. 

Outside Sources of Water Inside Your Walls

Water has many ways of getting inside your home. Roof penetrations, such as skylights, vents, and chimneys, can be sources of water getting inside and leading to damp walls. Keep an eye on cracked masonry and deteriorating flashing around windows and doors, as they, too, can be potential sources of water intrusion.

If you notice damp patches or spots on walls or detect wet areas on your ceilings after a rainstorm, leaks are likely the cause. Swift action is vital in such cases, as these damp walls can cause immediate and long-term damage to your home’s integrity. 

Ice Dams

In winter, a substantial snowfall coupled with inadequate roof insulation, ventilation, or gutter systems can lead to the formation of ice dams.

Snow accumulates on your roof, and without sufficient insulation or ventilation in your attic, it melts from the heat inside your house. The frigid outdoor temperatures swiftly transform the melted water into ice once it reaches the gutters, resulting in an obstruction commonly referred to as an “ice dam.”

The dilemma is that the melted snow requires an exit route. In the absence of one, it becomes a potential hazard. The ice dam may force its way downward, causing the gutters to freeze and detach from your home. 

Alternatively, it may retreat onto the roof, infiltrating even the tiniest openings. This could lead to moisture seeping into the walls and potentially causing significant damage to the roof’s integrity. To avoid this happening, be sure to address your insulation, ventilation, and gutter systems regularly.

Inadequate Draining and Damp

Moisture can creep upward through porous materials via capillary action, akin to how liquid “crawls” up the edge of a paper towel. Your walls, constructed with materials like plaster and drywall, can draw moisture from the ground. 

This phenomenon, known as rising damp, leaves behind telltale mineral deposits and distinctive “tide marks” at the base of your walls over time. 

Penetrating Damp

Penetrating damp, distinct from rising damp, enters directly from an external source, often due to leaks. In regions like the mid-Atlantic, porous block and block wall seams in basements are vulnerable spots.

Drainage issues become more pronounced in areas with expansive soil, like Virginia. The pressure exerted by shifting soil can lead to bowing, buckling, or cracking of basement walls. These fissures, combined with moist soil around the foundation, serve as prime entry points for moisture. 

After a heavy downpour, this scenario can swiftly translate into damp walls, highlighting the importance of adequate drainage systems and proper maintenance.

Rain can cause wet walls in the home.

How to Fix Wet Walls 

The best ways to prevent moisture from rising and penetrating damp is through improving surface water drainage, repairing damages, and ventilating the space.

Improve Surface Water Drainage 

Good surface water drainage is a key part of combating rising and penetrating dampness. By diverting water away from vulnerable areas, you prevent it from reaching surfaces altogether. Solutions may include redirecting downspouts, adjusting property grading, or implementing French drains.

Repair Damages

Once you’ve improved the water drainage, repair the damaged structures to eliminate mold and prevent further damage.

Ventilate the Space

Make sure your home has adequate airflow. This allows surfaces to dry thoroughly, preventing future moisture problems.

When Your Roof is the Problem

Spotting and addressing roof issues promptly will go a long way toward preventing long-term damage. If you notice wet spots on ceilings or walls after rainfall or damp walls following heavy storms, it could indicate that your roof needs attention.

Contact Long Roofing First

All along the East Coast, Long Roofing is a name that’s trusted to help homeowners make the most of their house. Our trusted roof replacement specialists will walk you through every step of the process. Contact us today to get a free estimate.

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