Fact or myth – rising damp

Fact or myth – rising damp

Rising damp is a phenomenon experienced by some, disputed by many and understood by few. A lot of people simply don’t understand it and why it is unique from other damp problems. Here we will explore rising damp.

Where does it come from?

Rising damp occurs when moisture travels up from the ground through capillary action into the walls. It’s like placing a sponge on water with it wicking up into the sponge through the pores. Groundwater contains salts which can cause structural damage. It can also increase heat loss in the home affecting energy bills.

Could it happen to me?

A lot of houses have damp proofing methods incorporated in their construction. For a number of reasons, they may have stopped working effectively. Older houses may not have any damp proofing methods installed. Due to a number of different issues, over time damp may well penetrate the fabric of the building. It’s important to understand the structure type in order to confirm why and how it is occurring. Naturally with ground supported solid wall structures, moisture will penetrate and rise up the wall. Hence breathable plasters were used to allow the wall to let moisture in and subsequently evaporate. It is necessary therefore to fully check why the issue is prevalent prior to undertaking any works.

What should I look out for?

Signs of rising damp can be fairly obvious. Look out for damp patches by the skirting boards that are a yellow or brownish colour. Wallpaper bubbling or coming away from the walls at the bottom can also be an indication. Rising damp may cause the skirting boards to decay and break off. Potential black mould may grow on the reverse resulting in a musty smell. Rising damp will contain salts such that rubbing your hand around the damp patches can result in a crunching sound. Where possible, look at the brick underneath to see if this is wet as this can be an indication.

Could it be something else?

One of the main issues with rising damp is that it can be commonly mistaken for other things. A genuine diagnosis of the problem is fairly rare. Often rising damp treatment will go ahead for the wrong problem and will not have the expected positive results. The best way to be sure is to hire in a professional. They can double check all the symptoms and advise you according to their findings. This approach will serve to rule out any other potential causes for the issue you have noted in the property.

Is it simply condensation?

Rising damp can be mistaken for condensation as the symptoms are similar. Condensation can occur when warm moisture in the air comes into contact with a cold surface. The air cools the relative humidity increases to the point when the air becomes saturated releasing water onto the surface. This happens in areas where airflow is restricted.

It’s also likely to happen in areas where airflow is restricted. Behind furniture and in wardrobes is common and will cause damage to contents. Damp and mould behind furniture that has been pulled away from a cooler exterior wall can be mistaken as rising damp. This is because the wall will be wet. This isn’t always the case. It’s important to seek good advice about what is condensation and how it is affecting your property.

How can it be treated?

Treatment can begin once you are certain the problem is rising damp. A common treatment method is using damp proofing injection cream. This reverts to a liquid and will penetrate the wall by absorbing into the capillaries creating a water repellent barrier. We recommend that after any treatment the inner plaster wall may also need re-plastering. If you have any doubts the best approach is to get it treated by a professional. This will provide a greater chance of success and prevent it from happening again.