Dampness in Homes - Causes and Cures



Water, in its many forms is an ever-present fact of life for a homeowner. Households can use hundreds of litres daily. Lots of rainwater must be successfully shed by the roof and cladding during storms. Groundwater moves through the soil beneath the foundations. Indoor humidity levels are controlled for comfort. 

Moisture in the form of condensation and water vapour is absorbed and released by the home itself. Uncontrolled water in our homes can cause damage. It can lead to damp unhealthy living conditions and mould growth, rotten wood, and structural damage. 

The exterior surfaces of a house from roof to foundation make up its envelope which is designed to keep out water. If it fails, expect trouble. When roofs, flashings, foundation walls and cladding are not properly maintained rainwater will find its way into the vulnerable parts of the house. 

All houses must absorb and release moisture consistently to maintain a healthy balance. If the house has “breathing problems” many types of moisture problems can develop. Trapped moisture can cause fungus and mould growth causing decay, rot, and eventually structural damage. Dampness destroys the value of the insulation and raises heating costs. 

Foundations - The best foundation is a dry foundation, groundwater, floodwater or even rainwater from misdirected downpipes and leaking gutters can undermined the foundations and cause settlement cracks and wet floors and walls. Cracks in the cladding and unsealed penetrations can cause water damage to the walls.

The most common sources of moisture problems at the exterior of a home include - Roof and Flashings - Roofs wear out, rust, shingles become loose, flashing around chimneys, plumbing vents and other penetrations fail. Low pitch roofs are particularly vulnerable. 

Gutters and Downpipes - Clogged gutters can cause water to back up and flow inside the walls and collect at the foundations. All downpipes should be connected to the public stormwater system to take water away from the house. 

Soffits and Facias - Damaged soffits (horizonal) and facias (vertical) can allow rain to enter the attic which can damage the insulation, ceiling, and walls. 

Landscape and grading - Installing flower beds up to the base of the cladding can cause surface dampness to suck up the wall and cause wood frames to rot. Grading should always allow water to flow away from a house.

Windows and Door Flashings and Seals - Cracked, torn or damaged seals, flashings, flashings around windows and doors can allow wind borne rain to penetrate your house. 

Common Interior Moisture Problems: In the walls and the attic and below the floor are many pipes with many joints or connections. They carry hot and cold water and wastewater to, around and away from the house. 

The effects of leaky pipes inside walls are not always seen for some time but can cause serious damage. Poor 

ventilation of kitchens, bathrooms and laundries can cause mould and dampness inside these and other areas of the house. 

Always vent to outside, not into the attic. Condensation from many sources - showers, hot baths, drying wet clothes inside. All these things produce moisture and without good ventilation will cause condensation and damage to surfaces such as windowsills. 

Regular Inspection and Timely Maintenance. Prevention is better (far cheaper) than cure. Catching a problem early and fixing it can save thousands of dollars. A Buyer’s Choice Home Inspections offer a full home inspection covering every 

aspect of moisture (including moisture readings) in your home. A very good investment that could save you thousands.