Rising damp is one of the most common structural problems in buildings, especially in older homes or those built on land with a high water table. It occurs when water from the subsoil rises through the pores of materials such as bricks, cements or stones, negatively affecting walls and floors. This phenomenon not only deteriorates the walls aesthetically with stains, mold or spalling, but also compromises the structural health of the building and interior comfort.
Table of Contents
Capillarity or negative pressure humidity
Capillarity is, in essence, a physical phenomenon that occurs when water rises through the pores of building materials, such as bricks, mortars, stones or cements, due to their absorption capacity. This action is similar to what happens when we introduce a piece of absorbent paper in a glass of water: the liquid rises through the material against gravity. In the case of buildings, this process allows subsoil moisture to rise slowly from the foundations to the walls, generating what is known as capillary dampness.
This type of moisture can cause numerous problems, such as stains, peeling paint or plaster, mold, odors and even loss of structural properties in the affected materials. That is why it is essential to identify it in time and apply effective and lasting solutions, because if action is not taken quickly, the damage can progress and affect both the health of the occupants and the stability of the building. Correctly combating capillarity not only improves the aesthetics of the building, but also guarantees its long-term conservation and habitability.
Main methods for the elimination of rising damp
There are various systems that attempt to provide a solution to rising damp, but not all are equally effective or durable. The following is an analysis of some of the most commonly used:
- Injections of water-repellent resins: the walls are perforated to inject water-repellent products. Although they can work in the short term, their effectiveness depends on the condition of the substrate and the correct execution. In addition, they may require re-treatment and do not eliminate the humidity already present.
- Anti-humidity coatings: consist of applying waterproof coatings on the affected walls. These products, such as special paints or mortars, are easy to apply but only act superficially. They do not prevent moisture from continuing to rise through the internal structure of the wall.
- Active or passive electro-osmosis: devices are installed that reverse the polarity of the water, forcing it downward. It is a costly solution, difficult to maintain, and does not always work in all cases.
- Air chambers or linings: false walls are created in front of the damp walls. Although they improve the aesthetics, they do not solve the root of the problem, and humidity continues to damage the structure behind the cavity.
G-FLEX - one of the best solutions against rising damp
Faced with these options, one of the most effective, durable and simple methods of installation is the use of nodular sheets such as G-FLEX, developed by Estil Guru. This solution stands out by creating a physical barrier between the wet wall and the new cladding, allowing moisture to dissipate and preventing it from being transferred to the interior.
The G-FLEX sheet is a high density polyethylene (HDPE) membrane with a nodular structure, specifically designed to treat moisture problems due to negative pressure, such as those caused by capillarity. Its main advantages are:
- Total waterproofing: prevents water from penetrating into the interior.
- Durability and resistance: withstands heavy loads and support movements without deterioration.
- Easy installation from the inside, without the need for costly exterior work.
- Efficient vapor management: its nodular structure allows air circulation and moisture dissipation.
- Compatibility with floors and walls: ideal for both wet floors and underground walls.
In addition, G-FLEX comes with a 10-year manufacturer’s warranty, making it a reliable solution for both new construction and renovations.
How is G-FLEX installed to solve rising damp?
The installation of G-FLEX is simple and can be done without the need for heavy machinery. It is mechanically fastened with screws and special washers (G-WASHER) to the support, leaving a small space at the top and bottom for ventilation. The joints between sheets are sealed with waterproof cement and W-S BAND strips, guaranteeing complete watertightness. Subsequently, the final coating is applied in complete safety.
This system also allows the incorporation of drainage channels for extreme cases where there is free water, leading the water to a sump or pump and guaranteeing the total elimination of excess humidity.