What Causes Penetrating Damp?

There are many different types of penetrating damp issues that can affect a property. The best way to treat the problem is to learn about what are the causes of penetrating damp problems in the first place.

Before looking at the causes of penetrating damp it is important to understand what penetrating damp is. Penetrating damp, which is also called lateral damp or water ingress, is where dampness passes from the outside of the property through to the inside.

Penetrating damp is not fussy about the age of the property or at what height it occurs – no property is safe! If left to its own devices a penetrating damp issue can cause further issues including unwanted damage to walls, floors ceilings and in some cases can lead to the rotting of timbers.

Penetrating damp issues can be more prevalent in older properties that were not built with a cavity between the walls and the walls are therefore of solid construction.

Causes of Penetrating Damp

The causes behind a penetrating damp issue tend to be down to what is known as building defects and can be wide and varied. Here though are some of the most common causes of penetrating damp issues found in the UK.

Damaged or faulty rainwater goods

One of the most common causes of penetrating damp is rainwater goods that in some way or another are defective and no longer functioning as they should. Rainwater goods in layman terms it is gutters and downpipes. It has been estimated that an incredible 1 in 5 houses is the victim of rainwater goods that are defective.

Most guttering and downpipes that are installed on modern properties nowadays tend to be made of PVC as opposed to the more traditional cast iron. It is still very common to find cast iron rainwater goods still in use on older properties.

Iron, although aesthetically pleasing, has a major disadvantage though over PVC. The harsh reality is that iron, no matter how thorough the maintenance routine is, will be susceptible to corrosion from exposure to the elements.

Through our experience, we often find that issues tend to occur on the back of downpipes made from cast iron as it is often the back that is neglected as it is hard to maintain whilst the front may benefit from regular maintenance.

Gutters fail predominantly as a result of blockages. Any blockages in the gutters will cause issues especially in periods where there is heavy rainfall as they will not be able to cope with the volume of water and as a result will leak or overflow. This in turn will then lead to the external walls beneath the gutters potentially becoming saturated with water.

Common forms of blockages include leaves, moss and other various forms of foliage all of which can be easily removed as part of a regular maintenance routine.

Defects with brickwork

If the brickwork is not kept in tip-top condition it can become a cause of penetrating damp issues. If bricks become spalled and the pointing has failed the brickwork loses its ability to withstand the elements and can allow moisture to penetrate through to the internal walls of the property.

This problem will only increase the longer the brickwork is left in that condition. When it is apparent that a property has damaged mortar joints and spalled brickwork repair work should be carried out along with repointing as necessary.

Porus brickwork

As bricks age their ability to defend a property from the elements, such as rain, becomes less and as such, they can allow penetrating damp issues to raise their ugly head. Bricks can also become porous as a result of frost or actual physical damage. If a property has a pebbledash finish that has not been maintained this could also lead to penetrating damp issues occurring.

If brickwork becomes porous water can penetrate the brickwork and penetrate deeply through to the inside of the property.

The more the property is subjected to rainfall the worse the problem will become leading to unsightly damp patches appearing on internal walls which will grow in size during periods of heavy rainfall as more water penetrates.

One of the best ways to treat porous bricks is to use a water repellent treatment on the brickwork such as Timberwise WeatherTek which is a masonry protection cream that will provide brickwork with a high degree of water repellency whilst still allowing the property to breathe.

Defects on the roof

The roof of a property can be a source of several defects that can lead to penetrating damp issues. Roof tiles and roof ridge tiles may be missing or damaged which can lead to moisture penetrating the inside of the property.

The flashing around the chimney is also a common source of water ingress if it becomes damaged. As these potential issues are on the roof they can sometimes be easily overlooked as they may not be easy to spot.

Door and Window frames

Gaps and cracks around window and door frames are common faults that if left will lead to problems with damp further down the line. As part of routine maintenance on your property, these should be checked and if necessary a flexible frame sealant should be used to keep moisture at bay.

It is also worth looking underneath the window sill to check the condition of the ‘drip groove’ The function of the ‘drip groove’ is to prevent water from running from the sill onto the wall. If this is damaged or not present at all action should be taken.

Uneven ground levels

Where the external ground levels are higher than the internal floor level and are higher than the damp proof course what is known as bridging can occur. As a result of bridging any dampness contained within the soil against the wall penetrates through the wall.

With homeowners desire to improve their properties they can inadvertently cause a penetrating damp problem in the process. A new driveway could unintentionally breach the level of the existing damp proof course and could also lead to misdiagnosis as a cause of rising damp.

Likewise, landscaping the garden and adding features such as large planters or raised flowerbeds may look attractive but could also lead to problems with dampness.

To make things worse with flowerbeds and planters we tend to add more moisture to the soil as we water the plants! At below ground level, if the property has a basement or cellar by their very nature, they are surrounded by damp earth and will undoubtedly suffer from damp issues unless properly waterproofed.

Contact our Penetrating Damp Specialists

If you are unsure of the cause of a penetrating damp issue then we have damp specialists across England, Wales and Scotland! It is important that any penetrating damp issue is identified and treated quickly to ensure that the penetrating damp does not lead to further unwanted issues. To learn more about penetrating damp visit our “what is penetrating damp?” page.

For further peace of mind, our damp specialists undergo training through the Property Care Association and hold the industry standard qualifications. Call our penetrating damp specialists today on 0800 288 8660 to receive the right penetrating damp solutions advice or click the link below to arrange a survey online.