Signs of Dampness in a House

Updated April 17, 2017

Excessive dampness or moisture can cause mould and mildew to grow in your home. Mold and mildew can in turn damage furniture and other items, create structural problems in the house and cause asthma and allergy symptoms. Dampness may come from a variety of sources, including baths or showers, firewood stored indoors, plumbing leaks, humidifiers and aquariums. Knowing the signs of dampness can help you fix a moisture problem before the damage becomes extensive.


Condensation on windows or other surfaces often represents a sign of dampness in a house. Frost or ice similarly indicates excess moisture in the air.


Wall or ceiling discolouration also signals excessive dampness. Discolouration is usually caused by mould and mildew, which are types of microscopic fungi. Discolouration may appear black, white, orange, green or brown.


A musty odour often represents the first indication of a dampness problem. You may smell the presence of mould or mildew or the scent of something rotting. In a humid environment, normal household smells may also linger longer or have a more intense smell.

Peeling Paint

Paint can be damaged by excess moisture, so paint that peels, blisters or cracks often signals a moisture issue. Similarly, concrete or masonry that crumbles or chips may indicate water damage.

Wood Deformation

Moisture causes wood to swell; it often then warps once dry. Deformed wood therefore often signals excess dampness. Advanced moisture damage can cause wood to rot or decay. Rotting wood may feel soft or exhibit signs of fungal growth, like mould or mushrooms.

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About the Author

Rebekah Richards is a professional writer with work published in the "Atlanta Journal-Constitution," "Brandeis University Law Journal" and online at She graduated magna cum laude from Brandeis University with bachelor's degrees in creative writing, English/American literature and international studies. Richards earned a master's degree at Carnegie Mellon University.