To stop damp from coming through walls, first identify the cause. Rising damp requires a new chemical damp-proof course (DPC). Penetrating damp is caused by structural leaks. Condensation is best managed by controlling moisture and improving indoor ventilation.
To effectively stop damp on walls, you first need to identify the cause: condensation, rising damp, or penetrating damp. Once identified, apply specialized treatments like damp-proof paints, moisture-absorbing devices, or waterproof membranes to create a protective barrier and resolve the root issue.
Penetrating damp is caused by moisture entering from outside. It often appears as damp patches on external-facing walls. Penetrating damp won't go away until the external issue is addressed – dehumidifiers help manage moisture but cannot fix the structural cause.
To permanently fix damp walls, you must first identify and eliminate the underlying cause: condensation, rising damp (moisture wicking from the ground), or penetrating damp (leaks from outside). Once the source is resolved, implement proper damp-proofing and ventilation to restore the wall.
Direct warm air at small damp patches to lift off surface moisture and condensation. Run a dehumidifier to remove excess moisture and address the issue of moist air. Improve ventilation by opening windows so that you have plenty of fresh air.
Damp refers to unwanted moisture within a building such as condensation on a wall or window. Mould is a fungus that grows when that moisture is present. Put simply, damp creates the conditions in which mould can flourish and thrive. You don't usually get mould when there is no moisture.
Condensation, leading to mould growth
This is by far the most common cause of damp and mould within properties, particularly during the winter months. As the weather gets colder and heating is turned on, windows are generally fully closed.
Mold is generally at its worst from early spring through early fall (specifically July through October), peaking during the warmest and most humid months. Mold thrives in warm temperatures (60∘F to 80∘F) combined with relative humidity levels above 60%.
Drying out a damp wall with a dehumidifier takes anywhere from a few days for minor surface dampness to several weeks or months for deep-seated water issues. The exact timeline largely depends on the material, the source of the dampness, and the dehumidifier's capacity.
To kill mold permanently on walls, you must eliminate the moisture source and use EPA-registered fungicides like RMR-141 or Zinsser Mold Killing Primer to kill roots and prevent regrowth. The process requires removing damaged, porous materials, applying a specialized cleaner, and sealing with specialized paint.
Opening your windows does temporarily purge humid air, but it cannot override the structural causes of persistent damp in your property. That brief surge of airflow feels reassuring: Persistent window condensation may clear from the panes, and the space smells fresher.
Polycell Damp Seal Paint has been specially formulated to seal patches of penetrating damp on interior walls and ceilings in just one coat, preventing them from showing through and spoiling decorations.
Do surveyors check every wall for damp? Surveyors will check visible walls, floors and ceilings, but they won't necessarily use moisture meters on every wall. If there are no apparent indicators of damp, moisture readings may be taken at random.
Staying in your home while you clean
Your whole community may be affected. If you have to stay in a moldy home, you need to take steps to reduce your exposure to mold. If you have asthma, COPD, or if you are immune compromised you should not stay in a moldy home, or even be there while it is being cleaned.
Yes, dehumidifiers will dry out damp walls, but primarily for surface dampness and high room humidity. They reduce the moisture in the surrounding air, which encourages the water trapped in the wall's plaster or drywall to evaporate.
Early signs of mold exposure frequently mimic seasonal allergies. They include sneezing, a runny or stuffy nose, coughing, postnasal drip, and red, itchy, or watery eyes. Skin irritation or rashes may also occur, and mold can trigger or worsen asthma symptoms like wheezing and chest tightness.
Additionally, spraying a solution of equal parts vinegar and water or a diluted hydrogen peroxide solution into the air can help to kill airborne mold spores.
The ideal temperature is between 77 and 86 degrees Fahrenheit. During the summer months, temperatures are often higher than normal inside the home. Make an effort to keep temperatures inside the home lower during the summer months. Setting the thermostat to the low 70s makes it more difficult for mold to grow.
If air gets cold, it cannot hold all of the moisture produced by everyday activities and some of this moisture appears as tiny droplets of water, most noticeable on windows on a cold morning. It can also be seen on mirrors when you have a bath or shower and on cold surfaces such as tiles or cold walls.
"Damp diseases" typically refer to illnesses and symptoms triggered or exacerbated by living, working, or playing in damp, moldy indoor environments. Exposure can cause respiratory issues, allergic reactions, and worsen existing conditions like asthma.
The four primary types of damp in residential properties are condensation, rising damp, penetrating damp, and traumatic damp. Identifying the type is crucial for treatment: condensation is caused by moisture in the air, while rising and penetrating damp involve water entering from the ground or exterior, and traumatic damp stems from sudden damage.
Common signs of damp
Excessive water droplets on windows or walls. Dark patches of mould on the walls, floors, ceilings, or around windows. Rotting or damaged skirting boards. A white residue left in walls and floors when soluble salts dissolve.
To kill mold permanently, you must combine targeted remediation with moisture control. No product works permanently if the source of moisture remains. The most effective approach includes using specific biocides, removing infested porous materials, and managing your home's humidity.
In A Nutshell: Misconceptions About Mold
Your home can be 100% mold-free: No, there are always mold spores in the air. Anyone can effectively remove mold: No, you need professional services for that.