The following provides some information as to the explanation why damp ingress may occur in buildings:
There are 5 main causes of damp:
- Rising damp
- Lateral damp
- Rainwater penetration
- Water leaks
Whereas rising damp can only occur where moisture is rising from ground level, penetrating damp, can occur anywhere in the fabric of the building, either horizontally or falling.
Here we have listed some of the causes penetrating dampness can include:
- Frost damaged, spalled bricks and damaged mortar
- This occurs where the face of the external bricks becomes, or is porous. The bricks absorb water and during cold periods, where the water freezes it will expand and the result is spalling of the brick surface. This then allows the bricks to absorb even more water during periods of wind-driven or heavy rain.
- Defective external joinery or other materials used for door and window frames
- Where frames are not properly sealed between the frame and the brick surround, water ingress will occur, which leads to tell-tale signs of dampness on the inside of window and door reveals.
- Leaking over-flow pipes
- Easily forgotten but a constantly leaking overflow pipe can cause substantial wetting of walls. The remedy may be simply adjusting or replacing the ball-valve in a cistern or water-tank.
- Defective rain-water goods such as blocked guttering and down pipes, blocked hoppers and issues with roofing such as malfunctioning flashing etc.
This is one of the main causes of water ingress above ground level and can lead to very significant damp and timber decay (dry and wet rot) problems internally. When the weather is good, people tend not to think of external rainwater goods. The best time to check all the gutters, down-pipes, hopper heads etc. around your property is when it is pouring with rain. Grab an umbrella and walk around your house to check that gutters, down-pipes and hoppers are not over-flowing or leaking. It is worth getting wet for!
If damp-patches increase or become darker following rain-fall, this suggests that the cause of the damp is related to rain penetrating the property. There may be drips or puddles beneath the area and visible staining may occur in the area, which is usually green in colour.
Penetrating damp can be prevented, to some extent, by ensuring that your property is well maintained externally and that gutters/downpipes are regularly inspected and cleaned. This can include checking poorly fitting joints. Any storm damage should be addressed as soon as you become aware of it. If issues are not rectified when they first become apparent, then additional problems such as timber decay to timbers adjacent to damp masonry may occur internally.
Often water can also become trapped behind the external renderings, which has suffered from cracks or where the render has blown and become hollow from the substrate. This then means that it therefore has no means of escape, leaving evaporation and drying to pass internally.
If you would like to discuss any possible problems you may have in relation to damp, please speak to one of our qualified Surveyors
who will be pleased to be of any assistance to you.
Our contact details are:
Tel: 01276 66466