To stop damp in your house, you must first identify the type of damp you are dealing with: condensation, rising damp, or penetrating damp. Once identified, combat it by improving ventilation, running dehumidifiers, and repairing exterior leaks or structural issues.
Increase ventilation
Reducing household humidity naturally comes down to three main strategies: controlling moisture at its source, maximizing airflow, and using DIY natural moisture absorbers.
To draw moisture out of a room, use a dedicated dehumidifier, or natural absorbers like DampRid, calcium chloride, and baking soda. Active methods include ventilation with fans, air conditioning, and placing desiccants like silica gel in enclosed spaces.
Fixing damp in a house depends on its root cause. The three most common types are condensation, penetrating damp (leaks), and rising damp (ground moisture). Follow the specific, targeted solutions below based on your issue.
Damp and mould within the home can produce allergens, irritants, mould spores and other toxins that are harmful to health. Even if visible mould is not present, dampness alone can increase the risk of health problems.
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.
Rock salt: Place bowls of rock salt in damp areas like closets or basements. It draws in moisture and requires no energy. Charcoal briquettes: Like rock salt, they absorb humidity and can be placed discreetly around the home.
DampRid bags work through a simple chemical process that pulls excess moisture out of the air and traps it as a liquid. They act as a passive, non-electric dehumidifier.
To fix high humidity in your home, target the primary moisture sources and improve airflow. The ideal indoor humidity is between 30% and 50%. Use your air conditioning, run exhaust fans while cooking or showering, seal drafts, and invest in a dehumidifier.
The cheapest and most effective homemade moisture absorber uses calcium chloride (sold as bulk driveway ice melter) combined with a simple two-bucket or colander-over-bowl system. This DIY approach costs a fraction of commercial products like DampRid and works identically to pull water from the air.
So, why is your house so humid, and what causes high humidity indoors? The short answer is that more moisture is being trapped indoors than your HVAC system can remove. Air leaks, poor ventilation, or an air conditioning system that's not working correctly can all exacerbate the issue.
Heating air lowers its relative humidity, but it does not remove moisture from the room. As air warms, its capacity to hold water increases, which spreads the existing moisture out and makes the air feel drier. For true moisture removal, you need ventilation, air conditioning, or a dehumidifier.
Using damp proof membranes are a great way to damp proof walls as they are easy to install and also extremely flexible. This flexibility means that they can cope with structural movement, which ensures your damp proofing lasts for decades.
Your house likely feels damp because of trapped indoor moisture, poor ventilation, or outside humid air seeping in. Common triggers include unvented showers and cooking, leaking pipes, poor insulation, or an oversized air conditioner that cools the air too quickly without removing moisture.
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%.
Moisture in a house is primarily caused by everyday human activities, poor ventilation, and unwanted water intrusion. Excess humidity can lead to condensation, mold, and damage if left unaddressed.
When comparing average sized, or average capacity dehumidifiers versus average sized air conditioner units, it is almost always cheaper to run the dehumidifier. Although energy efficiency has improved through the years, air conditioners use more watts of energy to operate.
Initial drying: When using a dehumidifier in a damp space for the first time, run it continuously for 24 to 48 hours on a low humidity setting (around 30%) to thoroughly dry the area. Regular use: To maintain a comfortable humidity level (30–50%), running the dehumidifier for 8 to 12 hours per day is often sufficient.
Choose DampRid for small, enclosed spaces without electricity, or electric dehumidifiers for continuous, whole-room humidity control. DampRid is cheap and passive, but dehumidifiers cover large areas, remove moisture much faster, and don't require constant refills.
The best places to put DampRid are in small, enclosed, or high-humidity spaces with stagnant air, such as closets, bathrooms, laundry rooms, and pantries. Place it on a flat, stable surface (like a high shelf) or hang it out of reach of children and pets.
However, some customers have experienced issues with leaking bags and the durability of the hangers.
Not only can baking soda help remove unwanted odors from your home, but it also has a high water absorption capacity, which can remove moisture in wet air. Simply leave a bowl of baking soda in a room with excess humidity. The bigger the room, the more baking soda you'll need.
Signs of High Humidity
Condensation on Windows: If you notice water droplets on the inside of your windows, it's a sign that there's too much moisture in the air. Mold Spots: Mold loves damp environments. If you're spotting mold in corners, on walls, or in the bathroom, your home's humidity is too high.
Moisture is drawn out by desiccants (moisture absorbers), mechanical appliances, and proper air circulation. The specific agent depends on what you are drying.