Moisture on the Wall: Causes and Solutions
It’s a problem that makes no distinction: it appears in old and new buildings, in apartments and houses, in the city or near the sea. Learn here about the causes, the solutions, and useful information to get rid of it permanently!
Moisture is defined as the unwanted presence of water or water vapor in a building’s structure, either in solid form (wet surfaces, stains) or gas form (air humidity). Acceptable humidity levels indoors typically range from 25% to 50%, with higher levels leading to mold (a harmful fungus that spreads quickly on the surface) and visible damage. From a construction standpoint, moisture causes deterioration of plaster (bubbling), paint, and metal elements within walls (corrosion).
Clearly, moisture is not just a structural issue for a building but also a health concern for its occupants. Excess humidity and the resulting mold can cause serious respiratory problems (cough, asthma, upper respiratory infections), negatively affecting quality of life.
Therefore, regular inspection, timely waterproofing, and proper repairs are essential steps for protecting both people’s health and the value of the property.
Types of Moisture and Their Characteristics
Moisture moves upward, downward, and sideways through the pores of building materials. There are three main types of wall moisture:
- Rising damp (from the bottom up): Water is absorbed from the ground through the pores of the wall, causing moisture to appear low on the walls.
- Lateral moisture: Often due to rain driven by strong wind penetrating the exterior walls.
- Top-down moisture: Caused by poor waterproofing of terraces or roofs, allowing water to enter through external elements such as rain, cracks, damaged gutters, or porous materials on rooftops or upper-level apartments.
The causes behind moisture typically involve the absence of waterproofing layers, poor interior or exterior sealing, increased vulnerability due to location (e.g., coastal or riverside areas), faulty gutters (especially in older buildings), or internal plumbing leaks.
Moisture High on the Wall: Main Solutions and Materials
Addressing moisture depends on the type and cause, but professional intervention is always necessary for a lasting solution. Repair, sealing, and waterproofing are jobs best left to experts. Still, it’s helpful for everyone to understand the basics.
Generally, dealing with moisture starts with analyzing the type and root cause, followed by selecting the appropriate solution. This means first identifying the type through visual inspection, site assessment, and checking temperature differences.
Then, the surface must be cleaned (e.g., from mold), dried, damaged plaster or paint removed, and the surface repaired and restored, including waterproofing and repainting. In some cases, clever fixes can also be effective.
For rising damp, a damp-proof course is created: this is a horizontal and/or vertical barrier installed inside or on the wall (usually at its base) to prevent moisture from rising. It can be formed using various materials or techniques.
Using cementitious waterproofing with resins, combined with a dimpled membrane (“egg crate” sheet), is ideal. The dimpled membrane is made of polyethylene with protrusions shaped like eggs, which prevent moisture accumulation.
For top-down moisture (from roofs or terraces), it's essential to apply waterproofing products on the surface of the terrace. KRAFT Paints offers a wide range of waterproofing solutions, such as Total Proof™ PU-HYBRID, Total Proof PU Fiber 25, and cement-based options like Hydroguard Flex or Hydroguard Elastic (ideal for use under tiles), to ensure the problem doesn't return.
For lateral moisture, external thermal insulation provides a long-term and effective solution. It balances the temperature difference between the interior and exterior, reducing condensation. Other methods also add value, such as thermally insulating paints.
For example, 4 Seasons™ Waterproof is a high-quality paint that protects against bubbling, peeling, mold, and algae. It’s easy to apply and provides excellent filling power, with strong adhesion to all typical building surfaces (plaster, concrete, brick), making it a reliable choice for moisture-affected areas (when used together with other waterproofing materials).
KRAFT Paints products are a trusted solution for addressing wall moisture and are preferred by top professionals for their performance and quality. Here you’ll find a complete range of repair and waterproofing productsfor walls and terraces, including elastomeric, liquid, and impermeable membranes, sealants, as well as cementitious waterproofing and repair mortars that can even be applied while the problem is still present.