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Worried about rising damp in concrete slabs? Well, to better understand what it looks like – it is something that occurs through a concrete floor slab and is fairly common when the moisture levels are too high and water is transferred to the finishing layer above the concrete. It occurs when a damp-proof membrane has either failed or was not installed at the time when the floor was initially laid.

In this article, we would have a look at an overall aspect of rising dampness through the concrete slab and what should and should not be done to avoid it and fix it.

Damp In Concrete Floors

We have already established how rising damp in a concrete floor occurs and we could safely say that the damp from the ground can make its way into the concrete floor. Due to the porous nature of the concrete, it is relatively easier to travel through the porous texture, causing issues or a slight rise in the flooring. Most of the time, changes in the surrounding environment are a major impact on the moisture levels within the concrete slab.

When you are faced with damp in concrete floors, there are two options available that you may want to consider:

  • An old concrete floor can be dug up and a new damp proof membrane could be installed which is to be lapped up by the edges before you replace the concrete floor.
  • Insulating the dampness in the floor completely using a surface Damp Proof Membrane (DPM).

How Do You Treat Rising Damp In Concrete Floors?

While we understand that damp floors and walls are a concern due to the moisture ingress and penetration, concrete floors especially could potentially create problems and are more difficult to solve. As mentioned earlier, due to the porous nature of the concrete floors, water moisture can rise up or travel through the floor and this could lead to damp floors, mould issues, and even concrete cancer.

Therefore, the easiest problems could involve isolating and repairing the leaking pipes. Most often, these are problems that can be fixed by solving or repairing the major source of moisture and also taking the necessary steps to help the damp floor dry out.

As mentioned in the above segment on what a damp in concrete floors is, we would be elaborating more on what causes the rising damp and how to treat it.

Damp-Proof Course Failure

These are problems that are more complicated to fix and are usually related to the damp rising up from the ground through the top surface of the concrete. Though these are problems less faced by newer buildings and houses (because they are constructed using tough plastic damp-proof membranes) than older buildings and houses (which were often built without damp-proof membranes).

Though this can occur even in newer properties when the damp-proof membranes are not installed properly or get punctured while building the property. While this is a tricky process, you could either use a traditional method of replacing the whole floor, as identifying the exact location of the defect would be difficult and is a time-consuming and expensive process.

Fixing such an issue requires either applying a damp-proof coating to the surface of the concrete or a damp-proof membrane could be laid at the top of the concrete during construction:

  • Damp-Proof Floor Coatings: A lot of the damp-proof floor coatings these days can be applied directly to the concrete floor surface using either a brush or a roller. While this is an easier part, preparation is the key with such coatings and the substrate must be in proportion, be sufficiently clear as well as dry. The type of coating you choose would depend on the intended use of the floor.
  • Physical Damp-Proof Membranes: There are several physical damp-proof membranes that are available like the Oldroyd XS Slimline Membrane that is quite often easier and quicker to install than using a damp-proof coating as they can be installed on still-damp surfaces that would further cause issues. However, they would always require a separate floor covering on top and would more likely require special attention on the floor or the wall junction detail.

Even though rising damp through concrete slab and salt damp in concrete would be a constant concern for home and building owners, it need not be an overly costly or a major problem to solve with the modern methods we have if it is detected at an early stage and is fixed with the correct method. With the right research on which method would fix the issue in the most efficient and cost-effective way, this would help at the right time.