Eight Causes of Damp on Internal Walls

Damp is a common problem in properties across the country. If left untreated, damp on internal walls can cause serious problems to your home.

There are three major types of damp that you could find inside your property: rising damp, penetrating damp and condensation. All three have varying causes and treatments, but knowing the underlying problems that can lead to them will help you keep damp out of your home in the long term.

So, what are the most common causes of damp on internal walls?

1. Your Damp Proof Course Is Broken

Modern homes have a damp proof course (or DPC), which is designed to keep water from rising up from the ground and getting into the walls of your home. A damp proof course can be made of plastic, but more modern (and effective) DPCs are chemical substances injected into the walls.

A damp proof course is there to stop rising damp from affecting your home. Rising damp occurs when water from outside gets into the walls and begins moving upwards. This occurs if your damp proof course is broken. Rising damp can cause serious structural problems if it begins to affect large areas of your property.

2. Your Home Has No Damp Proof Course

Modern houses are fitted with damp proof coursing as standard, as it’s the most effective barrier against rising damp. However, older houses (houses which are a hundred years old or more) were never fitted with damp proofing and may never have been upgraded to include it.

If you have an old home, it’s good practice to investigate whether there’s a damp proof course or not. If not, you should consider fitting one for long-term damp proofing.

3. Faulty Structures

For damp to occur, there needs to be a source of water or moisture. Often, this water accidentally seeps into your home and begins affecting internal walls when it leaks through faulty building structures (what we call penetrating damp).

If there are broken tiles on your roof, cracks in the walls, broken windows, doors, or any other number of faults with the structure of your home, then penetrating damp can occur when water begins to get through.

4. Leaking Pipes and Faulty Plumbing

One major cause of damp inside your home is leaking pipes, usually due to faulty plumbing. While you’ll notice a major leak quickly, the worst culprits are the small leaks that often go unnoticed for some time.

These small leaks build up over time and cause damp in walls and timbers. This weakens the walls, damages the plastering and, in severe cases, could even cause collapse.

5. Broken or Overloaded Gutters

Your outside guttering can also cause major damp problems if it’s not in working order. Gutters are there to channel rainwater away from the walls of your home, but if they’re blocked or broken, water builds up and can’t be dispersed.

Instead of being channelled away, rainwater seeps into the roof or walls, or pools on the floor and seeps in through the groundwork. Broken gutters need to be fixed, and kept clear of debris throughout the year.

6. Lack of Ventilation

One of the most basic causes of damp on internal walls is a lack of ventilation. If there’s a build-up of moisture in the air inside, this causes condensation (particularly in winter).

Condensation is a mild form of damp, but it still causes problems if left untreated. You can fix the lack of ventilation by leaving windows open after hot showers or by setting up a dehumidifier.

7. Cold Spots Lead to Condensation

Cold spots in your home can cause condensation and resulting damp problems. These cold spots cause condensation when hot air hits them.

While some cold spots can be removed through proper ventilation, serious cold spots are caused by cracks or gaps in the walls that let in cold air from outside.

8. Cement Rendering Causes Cracks

Cracks are a major source of moisture inside the home, which can lead to penetrating damp or condensation.

In modern homes, one of the biggest offenders is the cement rendering on your walls. This common building material tends to crack over time, leaving you with gaps and cavities that let water seep inside.

Danford Brewer & Ives has been providing damp proofing and prevention services to homeowners in Yorkshire, Teesside and North East England for decades. We’re happy to provide further information on the possible causes of damp in your home and explain how our team can fix it.

Please contact our friendly team on 01765 804050 or fill in our online contact form. Our technical team will be on hand with expert advice tailored to resolve your problem.