Wall humidity or damp walls are often considered a plague by homeowners, due to its adverse effects on both the house and its occupants.
Excess humidity damages the wall and even weakens the structural integrity of the building.Moreover, damp walls are vulnerable to mold and fungi growth. Occupants constantly exposed to mold and fungi can develop health issues such as allergies, migraines, body pain and cognitive issues. Hence, its extremely important to keep all your rooms and walls dry. This can be easily done with the help of a dehumidifier.
Here, is an updated A to Z of drying walls using a dehumidifier.
Damp walls- diagnosing the problem
You know you have a problem if your house has:
- A musty damp smell.
- Discolored or dark patches on walls and ceilings.
- Presence of mold and mildew on walls, ceilings and floor.
- Peeling wallpapers.
- Plaster boards which has salt formations on it.
- Condensation on window panes.
- Cold surfaces of walls, floors and ceilings.
- Tide marks
While these signs can help you detect the issue, you can confirm the problem of excessive humidity by trying out these three methods:
- Touch your walls with the back of your hand to check for dampness. If your walls are damp it will feel cold to the touch.
- Get an accurate reading using a damp meter or hygrometer which measures the amount of moisture in the air.
- Use a wall temperature gun to identify any cold patches on your wall.
Here is an infographic listing the various types of dampness prevalent in homes and the signs they exhibit.
Damp walls- the how and why?
The first step to tackling dry walls is to understand how dampness occurs. Understanding the root causes of damp walls can help you take the necessary actions to fix and also prevent future problems from arising.
The two main factors responsible for damp walls are – heat and humidity. Lack of outside venting prevents humidity from moving out of the room and instead causes it to accumulate within the space. The humidity gradually spreads out to the walls and other areas of the house where it forms condensation droplets as the warm humid air comes in contact with the cooler surface of the wall or ceiling.
Typically humidity is caused by:
- Indoor drying of clothes
- Taking frequent steam baths
- Leaking pipes and fixtures
- Poor rain water drainage system
- Water seepage and condensation through cracks and fissures in basements
In short the four main causes of damp walls can be categorised as:
- A defect in structure of the house
- Poor insulation
- Cracked pipework in the plumbing system
- Condensation caused by various activities.
Of these, most households report of condensation as the predominant cause of damp walls.
Identify and fix the root cause
The second step is to determine the cause of damp walls in your house. You might need to hire a specialist to investigate the situation and identify the exact cause. Once the cause (example- leaking tap) has been identified, take the necessary steps to fix it (arrange for a plumber). Other necessary measures can include:
- Replacing porous bricks or making them water repellent using a special silicone water repellent paint.
- Installation of damp- proof course.
- Insulating loft and walls.
- Double glazing window.
Be sure to fix your issues quickly as the health of your family depends on it.
Identification and fixing of core problems is an extremely vital step, as any fixes done otherwise will only serve as a temporary patchwork and lead to recurrent problems in future.
Drying walls with a dehumidifier
Now to move on to the third step – which is to dry your walls. You can do this by ventilating the room sufficiently by opening all windows and doors, or by placing a standing fan directly in front of the wall. However, these methods are slow in action. A faster method would be to use a dehumidifier to dry your walls.
True, there are other appliances specifically designed for the purpose of drying walls. But if your budget can’t be stretched to getting one of those, then using a dehumidifier is the next best idea.
How do dehumidifiers dry walls?
Similar to a vacuum cleaner, dehumidifiers have a duct through which air from the room is taken into the system. The drying mechanism of dehumidifiers is done through either refrigeration or by absorption/ adsorption methods.
- Refrigeration: The unit works similar to a refrigerator, removing the moisture by cooling the air. The unit has a grille on its side through which warm air is drawn in by means of an electric fan. The warm air is passed through refrigerant cooled pipes and transformed to chilled air. During the cooling process, the moisture is drawn in from the air and collected into the reservoir tank. The air is heated to its original temperatures by means of heated pipes and is circulated into the room through another grille.
- Absorption/Adsorption: The unit absorbs/adsorbs the moisture onto a drying material. Similar to the refrigeration method, here too air is drawn in via a fan and through a grille. However, once inside the system, the moisture content from the air is “soaked up” by means of a desiccant substance like silica gel or others. Dehumidifiers which work on this mechanism is more suitable for use in areas with cold weather conditions.
Placing the dehumidifier
Place the dehumidifier on the floor in front of the damp wall. Ensure that the system is standing upright. Keep the unit free from all obstructions and plug it in. Try to plug the unit in a nearby socket to avoid using extension cables. Before starting the dehumidifier, remember to close all windows and doors.
To accelerate the drying process, remove all objects, moldings and wall paper from the wall as they form a sealant causing water to accumulate within the wall.
Although drying the wall can be time consuming, it is imperative that you wait and ensure that the wall is dry before adding the finishing touches to it.
Note that while almost all electric dehumidifiers are capable of drying walls, remember that this is only a temporary solution.
This brings us to our next and final step which is to ensure that the humidity levels within your spaces are kept low. Here are some ways by which you can attain this goal:
Warm rooms: Set your thermostat to lower temperatures to keep your homes warm. Check and make sure that your central heating systems are functioning effectively to keep humidity at lower levels.
Ventilate: Open windows, install vents and use extractor fans to ventilate and remove excess humidity from your spaces regularly.
Maintain your homes: Regular maintenance of your homes can contribute greatly to reducing humidity levels in your homes. Repair all leaking fixtures and pipes immediately and regularly check your wall papers and plasters to ensure that your home is in a good condition.
Modify life activities: Drying your clothes outside, cooking with pots closed, shorter baths and ventilating your bathrooms are lifestyle changes that you could incorporate to safeguard your homes from humidity.
Although not a permanent fix, and until you can find a long-term solution, use of dehumidifiers to dry walls is certainly a good idea as it can help reduce the damage to the structure of the house and stop the growth of microorganisms that affect the health of inhabitants.
FYI: The Air Geeks' top-rated dehumidifiers tested in 2019:|
1. Frigidaire - FAD954DWD : the best of the best (very large rooms)
2. Homelabs - 70 Pint: great value (large rooms)
3. Homelabs – 50 Pint: good brand, good price (avg. rooms)
4. Black+Decker - BDT30WTA: a very good entry-level option (small rooms)