How to properly perform cut-off waterproofing. Capillary rise of moisture: how to deal with it?

It is impossible to fully shield the foundation from groundwater, no matter how meticulously it is waterproofed. From the building’s base, moisture rises and seeps into the walls. Consequently, the finish deteriorates, mold and moisture enter the room, and concrete structures eventually collapse. Cut-off waterproofing is intended to keep moisture from seeping through the foundation and onto the house’s walls.

Why cut-off waterproofing is needed and how to perform it correctly?

There is always some moisture present in the soil. The groundwater level rises at specific times (during the snowmelt season, after heavy rains), endangering the foundation from flooding. Horizontal cut-off waterproofing stops moisture from leaking into the walls from the base. This is carried out while the house is still being built.

The main goal of cut-off waterproofing is to establish a waterproof layer around the building’s whole perimeter, between the wall and the foundation. This objective is accomplished with a variety of techniques and resources.

Materials for the installation of cut-off waterproofing

Three primary kinds of materials are used in cut-off waterproofing. Every one of them has unique traits and working principles.

Fiberglass-based rolled coverings or fiberglass covered in a bitumen-polymer layer. It’s easy to understand how this moisture protection works: capillary moisture is retained by a waterproof sheet placed between the wall structure and the foundation.

When similar materials are used for the basic waterproofing of the room’s floor and foundation, this low-cost solution is typically used.

However, bitumen coatings have drawbacks, such as poor elasticity and poor resistance to low temperatures.

PVC membrane offers a benefit in this context. It maintains its properties at all temperatures and is robust, elastic, long-lasting, and resistant to harsh chemical environments. But, if bitumen coatings were applied to the foundation to protect it, then this kind of cut-off waterproofing is unacceptable. These substances are incompatible with one another because the polyvinyl chloride film breaks down when it comes into touch with bitumen.

Synthetic ethylene-propylene rubber, or EPDM membrane, is an additional roll coating option for cut-off waterproofing. It has none of the aforementioned drawbacks. The film is incredibly elastic, resistant to frost, and long-lasting. It also doesn’t tear when stretched. The EPDM membrane works well with all other waterproofing materials and is impervious to the effects of soil-borne salts.

Another application for penetrating compounds is horizontal cut-off waterproofing. This is a very efficient and modern method of protecting masonry and concrete.

The base becomes waterproof as a result of the liquid mixture’s deep penetration. The surface can still "breathe" at the same moment.

Cut-off waterproofing is done using a variety of compositions, such as silicate and siloxane, depending on the type of construction material.

Materials for injections: microcements, acrylate gels, polyurethane and epoxy resins. Their application is feasible not only for building but also for maintenance. If a building’s construction results in a capillary suction issue because the horizontal shut-off waterproofing was not finished on time, injection becomes the sole means of shielding the walls from water seeping up from the base.

Installation of cut-off waterproofing

The type of material used determines the technology for installing cut-off waterproofing in concrete and brickwork. Let’s quickly examine the two most widely used approaches.

Horizontal roll waterproofing with a cut-off. Cement mortar is applied to the foundation and used to attach the canvas to the surface. Its width is chosen so that the outside of the wall is about 50 mm. The base and floor’s waterproofing material is attached to the free edges.

Bitumen-polymer mastic, epoxy resins, rubber-based glue, and other compounds are used for this and for joining the sheets. Consider the type of cut-off waterproofing when selecting them. The rolled sheet is once more coated with cement before a wall is constructed using brickwork or concrete mortar.

Cut-off waterproofing with materials that pierce through. The sort of insulated surface dictates the installation technology. In order to increase the material’s penetration, the concrete is cleaned, seams are fined, and cracks are widened to a distance of two centimeters.

Brickwork that has been cut off from waterproofing needs different preparation. The entire base area is drilled with recessed areas that are 2-3 cm deep and spaced about 5 cm apart. They receive a wash and a plaster mortar filling.

Then, a newly made waterproofing mixture is applied after the concrete or brick base has been moistened with water. It is laid again after one and a half hours.

Capillary rise of moisture: how to deal with it?

Horizontal cut-off waterproofing is done while the building is being constructed. If everything is done correctly, there shouldn’t be any issues with the walls’ high humidity levels. In reality, capillary rising moisture frequently affects even new home owners. There could be a number of causes:

• poor-quality installation of the waterproofing layer separating the wall from the foundation, use of unsuitable materials;
• damage to horizontal insulation during the process of backfilling the foundation with soil, which may contain large sharp stones, reinforcement and other foreign inclusions;
• soil movement due to frost heaving, which also leads to deformation of the foundation and the appearance of defects in the insulating layer.

Even concrete that is waterproof can absorb moisture. The characteristics of the soil are the cause. The stronger the water rise, the denser the soil and the smaller the diameter of its pores. The rise in clay soils is at least 8 meters.

There must be an end to this phenomenon.

The main precautions are to use a high-quality foundation drainage system, backfill with clean sand, and shield the horizontal waterproofing coating from mechanical damage with a long-lasting material (profiled membranes are commonly used for this). Modern technologies can be used to solve issues that arise while a building or other structure is in operation. Injectable cut-off waterproofing is one of them.

This method’s benefit is that it doesn’t require disassembly, making it suitable for repairing structures. By using injection technology, you can repair the damaged water barrier and totally shield the walls from moisture that rises from the foundation and soil capillaries. It works just as well for cut-off waterproofing in concrete and masonry constructions.

Different compositions with different properties and mechanisms of action are used for injection. Materials that react with the components of a structure after entering its body are now widely used.

Strong crystals that resemble threads consequently form in the capillaries. They keep the moisture from penetrating further into the concrete by dislodging it.

The properties of injection formulations remain constant over time, and they can tolerate any load or temperature variation.

Various additives are used by manufacturers to produce injection materials. Some of them give the mixture more fluidity, which makes it easier for it to enter even the tiniest pores. Others give it the capacity to expand. Still others give it the capacity to function at negative temperatures.

The specifics of the injection technique vary based on the kind of composition and the isolated base, but in general, it consists of these steps. A checkerboard pattern of 1.5–3 cm diameter wells (holes) are drilled into the structure. Usually, they are positioned slightly angled toward the surface. Although the depth varies, it is typically 5–8 cm less than the base’s thickness.

To get rid of dust, water is forced into the crevices. Pump hoses are connected to special devices called packers, which are placed in the holes. A material for injection is pumped through them. The characteristics of the composition determine what comes next. Some start working right away after injection, while others take a month or two for the chemical reaction to finish.

Producers of cut-off waterproof membranes

A wide range of materials are available in the market for cut-off waterproofing of concrete, brickwork, and other surfaces. A brief synopsis of the most well-known manufacturers is provided below.

One of the top Russian suppliers of rolled bitumen-polymer materials is TechnoNIKOL. They have a sturdy polyester foundation and are coated in polypropylene on both sides, which guarantees strong adherence to cement mortar. Low water absorption, long lifespan (up to 50 years), and simplicity of installation are the materials’ distinguishing qualities.

Under the DELTA brand, roll materials are manufactured by the German company Dorken. These are polyolefin and synthetic rubber membranes with high strength. They work well with other materials for foundation insulation and are elastic, durable, and resistant to frost.

Cut-off waterproofing must be done correctly to stop moisture from rising through the capillaries in the foundation of your building, which over time can seriously harm the structure. In order to prevent moisture from rising through porous building materials like brick and concrete, a barrier must be created. You can keep your home dry and healthy by shielding it from moisture with efficient techniques and materials like bitumen or waterproof membranes. Learn how to properly install cut-off waterproofing and maintain a solid, moisture-free foundation by following our guide.

Manufacturer of a large variety of penetrating materials is Penetron. Both vertical and horizontal waterproofing can be accomplished with dry mixtures.

Video on the topic

Installation of horizontal cut-off waterproofing using injection method

Cut-off waterproofing for capillary suction (rise) of moisture.

There is no shut-off waterproofing, wet walls, how to fix it