Dampness in Building: Causes & Prevention

What is dampness in building?

The presence of unwanted moisture in a building’s structure, whether through condensation inside the building or infiltration from the outside, is known as structural dampness. Rain penetration and ambient climate dependent factors of condensation account for a significant share of damp issues in structures. Building dampness can be caused by poor design, faulty construction, and the use of low-quality materials.

The process of stopping water from leaking from the roof is typically referred to as water proofing. Whereas, the process of keeping the walls, floors, and basement dry is known as damp proofing.

Defects resulting from building dampness

Following is a summary of the defects that caused by building dampness: –

Bricks, stones, tiles, and other materials may eventually disintegrate as a result of the efflorescence which building dampness creates.
Plaster may become softer and crumble as a result.
It may result in paint flaking and bleaching, as well as the creation of coloured patches.
Timber might end up warping, bending, or decaying as a result.
Metals may corrode as a result of it.
Electrical fixtures might deteriorate as a result of it.
Termite growth can be seen.
It makes the occupants’ living conditions unhealthy.

What are the causes of building dampness?

The significant causes of building dampness can be summed up as follows: –

Dampness rising through the foundation walls. Due to capillary action, moisture from damp ground may rise significantly above the ground level.
Dampness may result from rainwater seeping through exposed wall tops, parapets, compound walls, etc.
Rainwater may seep through a damaged roof covering in the case of sloped roofs. Furthermore, faulty eaves course and eave or valley gutters may permit rainwater to enter the top supporting wall and result in moisture.
In the case of flat roofs, insufficient roof slopes, incorrect rainwater pipe connections, and faulty joints between the roof slab and parapet wall may prove to be the cause of dampness.
It can be due to leakage of piping system; the water slowly seeps into the walls or floorings.

How to prevent or solve the building dampness issue?

The following strategies are typically used to stop the dampness defect in a structure: –

Membrane damp proofing – This entails placing layers of water-repellent membrane between the source of the moisture and the part of the structure adjacent to it. Commonly referred to as a damp proof course (DPC), this kind of layer can be made of cement concrete, bituminous felts, mastic, asphalt, plastic or polythene sheets, and other materials. DPC can be installed either horizontally or vertically in floors, walls, etc., depending on the source of the dampness.
Integral damp proofing – To increase the concrete’s impermeability, several water proofing compounds are added to the concrete mix. Such chemicals are offered in both powdered and liquid forms on the market. Chalk, fuller’s earth, and other materials made from clay, sand, or lime help to fill the gaps in concrete and make it watertight. When combined with concrete, various substances such as alkaline silicates, aluminium sulphate, calcium chlorides, etc. undergo chemical reactions to make water-resistant concrete.
Surface treatment – It consists of filling the pores on surfaces that have been exposed to moisture. The building is thus well protected from the effects of heavy rain by the application of water-repellent metallic soaps like calcium and aluminium oleates and stearates. It includes bituminous solutions, cement coatings, transparent coatings, paints, and varnishes. In addition, lime cement plaster is the economical method to treat the building dampness. It has been discovered that walls that have been plastered with cement, lime, and sand in the ratio of 1:3:6 efficiently reduce wall moisture caused by rain.
Guniting – This involves spreading a thick layer of impervious cement mortar over the surface that needs to be waterproofed. Utilizing a device called as a cement gun, the procedure is completed.
Cavity wall construction – This consists in sheltering the main wall of the building by an outer skin wall leaving a void in between the two. The hollow blocks the passage of moisture from the exterior to the interior wall.
Pressure grouting – Cementation is the method or technique of applying pressure to the cement grout—that is, the cement, sand, and water mixture—in order to push it into any cracks, cavities, or fissures present in the ground or structural component. In other words, the cementation process consolidates and renders water-resistant all the structural parts of a building that are susceptible to moisture penetration.

Key Takeaways

Depends on the various conditions and situations of the buildings, it is important to determine the correct method that are suitable to treat and tackle the dampness issue for the building. We, Structural Repairs (M) Sdn Bhd have more than 30 years of experience in this industry. We adopted the advanced technology – Infrared Thermographic Scanning Camera to assist in detecting the issue of dampness in the building. The infrared camera can be used to identify location that cannot be seen using naked eye. It is used to detect hidden leaks in the building, such as moisture in an inner wall. In addition, infrared camera can provide the accurate or precise location of the damaged pipe and save the need to hack off the walls and floors which incur more cost to repair. The benefits of the infrared camera include: –

Detects moisture, dampness or leaking spots in flat roofs, ceilings, behind walls and under floors.
The result can be generated quickly.
Effective: The area/location can be identified quickly.
Efficient leak detection method: Minimize disruption and no damage to the building.