The severity of structural damp can vary. However, its presence is unwanted and, in some circumstances, can cause severe problems to the structural integrity of your home. Before you reach crisis level however, there are several steps you can take to reduce damp and prevent it from happening again. Please remember that damp can be very dangerous if left untreated. While the information in this blog is intended to advise, we always recommend employing the services of a professional.

damp cream wall with paint peeling

What is Structural Damp?

Structural dampness is the presence of unwanted moisture in a building and its structure. This damp can be a result of entry from the outside of the building or condensation from within. Long term effects on a building’s structure can include plaster deterioration, timber decay and possible adverse health effects for occupants. Old buildings are more susceptible to damp due to the materials traditionally used (pre-mid-19th century), allowing the moisture to be absorbed and then evaporated back out. Newer buildings are designed to block out the water initially, so the causes of damp are likely to be different.

Causes of Damp

Leading causes of damp come from:

Air moisture condensation – often a side effect from energy-saving measures, such as double glazing, that stop old buildings from breathing. It can also be caused by increased humidity from cooking and washing.

Penetrating damp – many areas can be weak points for allowing water to enter. Roofs, chimneys and poorly maintained drainage systems, such as guttering, can all be responsible.

Internal spillage – leaks, floods, and overflowing baths and showers can all be a culprit.

Below ground damp – often referred to as rising damp. It is caused by the evaporation of moisture below the property and aggravated by impervious floor coverings preventing the moisture from evaporating.

condensation in windows

Identifying Damp

You can keep an eye out for the symptoms of damp, however, accurately diagnosing which type of damp your home may have should be left to a professional. Condensation is a strong indicator of damp, evidence of which can be seen on hard, shiny surfaces or in the presence of mould. To identify penetrating damp, you should inspect the exterior of your property to try and identify areas of potential moisture entry. For example, missing roof tiles or wall cracks. Damp patches will commonly occur after heavy rain and other adverse weather conditions. A competent charted building surveyor should be able to provide you with a thorough damp report identifying the problem.

damp brick wall with green moss

How to Reduce Damp

There is usually a way to prevent and cure any type of damp. These solutions range from home improvements to full damp proofing courses. If the problem is being caused by penetrating moisture, it will be necessary to repair the area that is allowing the moisture through (wall cracks, roof etc.) Proper maintenance of guttering and drainage systems should also be practised. For rising damp, taking measures to allow your building to breathe is usually the best solution. This could be by repointing existing hard cement render with a lime-based mortar. Internal condensation can be treated to an extent by allowing proper ventilation, such as keeping windows open regularly. You can do this alongside a dehumidifier, but one should not be used as a replacement for adequate ventilation. Ensure that tumble dryers have an external vent and drying clothes inside the home should be avoided, and also keep the temperature of your home above the dew level. Keeping doors closed when having a bath or shower, or when cooking, can stop the moisture from entering other rooms in the house. Again, a chartered building surveyor undertaking a damp inspection will provide you with a professional solution for your damp problems.

For further details on damp reports, and other information on structural reporting and design, take a look at the Martin Perry Associates website. Based in the South West, we offer a wide range of structural engineering and surveying services.