Rising Damp in Houses
Rising damp is a common issue that affects many buildings, particularly those that are older and constructed with porous materials such as stone, brick, and mortar. It occurs when moisture from the ground rises up through the walls of a building, causing damp patches and other damage.
It is most commonly found in older buildings and is caused by a lack of damp-proofing, or a failure of existing damp-proofing
Causes of Rising Damp in Houses
Rising damp is caused by the natural process of capillary action, which is the movement of water through small spaces. This process is caused by the difference in air pressure between the inside and outside of a building. As the air pressure outside is greater than the air pressure inside, it causes the water to be drawn up through the walls of a building.
The most common cause of rising damp is a lack of damp-proofing. This is a waterproof barrier that is installed at the base of a building’s walls to prevent moisture from rising up through them. If a building is not damp-proofed, then moisture will be able to rise up through its walls and cause rising damp.
In some cases, existing damp-proofing may have failed. This could be due to a number of reasons, such as the damp-proof material being damaged or degraded over time, or the damp-proofing not being installed correctly in the first place.
Rising damp can cause a number of problems in a building, such as damage to walls and furniture, mould growth, and an unpleasant musty smell. It can also cause health problems, such as respiratory issues and allergies.
Signs of Rising Damp
Signs of rising damp can include;
- A “tide mark” on the walls: This is a visible line where moisture has risen up the wall and left a stain.
- Damp patches on walls and ceilings, Peeling or flaking paint or wallpaper: Rising damp can cause paint or wallpaper to peel or flake off the walls.
- A damp or musty smell: This is caused by the moisture in the walls and floors of the building.
- Rotting skirting boards or floorboards: Moisture can cause wooden fixtures and fittings to rot.
In some cases, there may also be evidence of mould and mildew. In extreme cases, the damp can cause structural damage to the building, such as crumbling mortar and weakened foundations.
The best way to detect rising damp is to look for the signs mentioned above. It is important to note that these signs may not be immediately visible, and may take some time to become apparent. If you suspect that you may have rising damp, it is important to seek professional advice and have the problem assessed and treated as soon as possible.
Rising damp can be treated in a number of ways, including the installation of a damp-proof course, which is a physical barrier that prevents moisture from entering the building. Other treatments may include the use of chemical damp-proofing agents, or the installation of a ventilation system to reduce the level of moisture in the air.
In order to prevent rising damp, it is important to ensure that the building is well maintained and that any potential sources of moisture are identified and dealt with. This includes ensuring that gutters and downpipes are well isolated from causing moisture seepage to the building walls.
Treatments for Rising Damp
Fortunately, there are a number of treatments available for rising damp. These treatments can be divided into two main categories: chemical and physical.
Chemical treatments involve the application of a chemical damp-proof course (DPC) to the affected walls.
- Installing a damp-proof course: If there isn’t a damp-proof course or it has failed, installing a new one can help to prevent rising damp. A DPC is a waterproof membrane that is inserted into the walls to prevent moisture from rising any further. The DPC is usually made from bitumen, plastic, water-proof concrete mixture, or a combination of each.
- Treating the walls with a damp-proofing agent: This can help to prevent moisture from rising up the walls.
Physical treatments involve the installation of a ventilation system to reduce the amount of moisture in the air. This can be done by installing air bricks, which are small openings in the wall that allow air to circulate freely. Alternatively, a mechanical ventilation system can be installed to draw moisture-laden air out of the building.
In addition to these treatments, it is also important to address any underlying causes of the rising damp. This may involve repairing any damaged or missing mortar, or replacing any damaged or missing bricks.
In some cases, it may also be necessary to replace the entire wall. This is usually done when the damage is too severe to be repaired.
Overall, rising damp can be a serious issue, but it is one that can be resolved professionally.
Prevention of Rising Damp
Fortunately, there are a number of ways to prevent rising damp from occurring. The most important step is to ensure that the building is properly waterproofed. This means that any moisture that enters the building should be prevented from getting into the walls and floors. This can be done by installing a damp proof course, which is a layer of impermeable material that is installed between the walls and floors of a building. This will prevent moisture from entering the walls and floors, and will stop any rising damp from occurring.
In addition to a damp proof course, there are other measures that can be taken to prevent rising damp. These include ensuring that the building is well ventilated, so that any moisture in the air can be removed. This can be done by installing vents in the walls and floors, or by opening windows and doors to allow air to circulate.
Another important step is to ensure that any existing damp is dealt with. This can be done by using a dehumidifier to remove any moisture from the air, and by using a fungicide to kill any mould or mildew that may be present.
The Impact of Rising Damp on Structural Integrity
Rising damp can have a serious impact on the structural integrity of the building. Rising damp occurs when moisture from the ground rises up through the walls of a building, usually due to poor drainage or a lack of waterproofing. This moisture can cause damage to the structural integrity of the building, as it can lead to the weakening of the building’s foundations, walls, and other structural elements.
The effects of rising damp on structural integrity can be far-reaching, and can include a number of issues. One of the most common is the deterioration of the building’s foundations, which can cause the building to become unstable and even collapse. The moisture can also cause the walls of the building to become weakened and can lead to the formation of cracks and other defects. This can cause the walls to become unstable and can lead to further structural damage.
In addition, rising damp can also cause a number of other issues. For example, it can lead to the growth of mould, which can be damaging to both the structure and the health of the people living in the building. It can also cause the paintwork of the building to become discoloured and can lead to the growth of other harmful bacteria and fungi.
The best way to prevent rising damp from causing damage to the structural integrity of a building is to ensure that the building is waterproofed and that all drainage systems are in good working condition.