There are three main types of damp
This form of damp is more common in older properties where there is no damp course or the damp course has failed over time. With rising damp water is absorbed up through the foundation of a wall to around one meter in height. The wall acts as a wick absorbing the water from the ground. Crumbling plaster, rotten skirting board, salt deposits and a tide mark are associated with rising damp. But because it is coming from the ground does not mean it always rising damp. With thermal imaging we can check to see if it is a plumbing leak or condensation due to a cold area in the wall from missing insulation.
This is where water comes in from the outside walls, roof or floor creating damp patches on the interior of the house. This will lead to damage to plaster work, timber and your interior finish. It also will leave conditions right for mould growth to flourish. Penetrating damp can be caused by many external construction defaults. But what sometimes looks like penetrating damp is actually condensation which appears around windows and doors with no thermal bridging, ceiling with missing insulation and corners of rooms because of their lower thermal value. With thermal imaging of the room you can see if it is condensation that is causing the damp and mould growth or penetrating damp. Damp walls from penetrating damp will conduct more heat and appear colder on the thermal imaging camera and a pattern of water ingress can be seen. We can also use a borescope to see inside the wall to confirm our findings.
This is easily the most common form of dampness in buildings new and old. The air in our homes can have very high levels of humidity due to the activities of the occupants such as cooking, washing, drying clothes and even breathing. A property with four people will produce 16 pints of water per day, that is 4 pints of water per person per day. This huge amount of moisture over 116 pints per week that most go somewhere.
In our homes the warmer the air the greater the potential for the air to hold water vapour. Air at 10 degrees is saturated when it contains 7.6g of water per kg of dry air. Air at 20 degrees is saturated when it contains 15.3g of water per kg of dry air, that’s just over double the amount of moisture. That why cool out door is far dryer than the air in our homes.
What happens if we cool the moisture laden air?
We know if we take a bottle from the fridge beads of condensation will flow down the bottle. The same happens when the moist air comes in contact with cooler surfaces in your house. This is called the dew point and beads of moisture will form leading to ideal growing conditions for mould growth.
The area in blue on the thermal image highlights the area at risk of condensation forming at that present humidity level.