FAQ – questions and answers

What does the PRINZ method involve?

The PRINZ method is a mechanical way of creating a horizontal damp-proof barrier in existing walls. Using specialized chain or wire saws, the wall is cut in one-metre sections, and a durable barrier — a PEHD sheet or fibreglass-reinforced polyester sheet — is inserted into the resulting gap. The individual sheet sections are “joined” with a 10cm overlap, creating a continuous, tight barrier that cuts off moisture rising by capillary action from the ground. System wedges of varying thickness are then driven into the gap to prevent the building from settling, and finally a special expanding mortar is pressure-injected, which together guarantees the building’s full structural stability.

Where does the method come from and how long has it been used?

The name comes from an Austrian manufacturer of specialized equipment for cutting building materials, building walls and inserting horizontal insulation. The method has been in common use for roughly 50 years, mainly in German-speaking countries, and over time, in the 1990s, it also gained recognition in Poland as one of the most effective methods of secondary horizontal waterproofing.

How does the PRINZ method differ from other wall-drying methods?

Unlike chemical methods (crystalline injection, pressure injection) or electrophysical methods, the PRINZ method creates a physical, material barrier in the wall — similar to the horizontal insulation installed at the building’s construction stage. It doesn’t rely on a preparation penetrating the wall’s structure, so its effectiveness doesn’t depend on the absorbency, salinity, or homogeneity of the building material.

How does the mechanical method differ from chemical injection?

The key difference is the certainty and durability of the execution. Chemical injection involves saturating the wall with a preparation meant to block the capillaries. Its effectiveness depends on the degree of wall dampness, its structure, and the precision of the drilled holes — the liquid may not spread evenly. The PRINZ method is a purely mechanical solution. We insert a physical, solid barrier through which water cannot pass, regardless of how wet or salty the wall is at the time of the works.

What material is used as the horizontal barrier?

In brick walls, thick 2mm, strong high-density polyethylene (HDPE) sheets are most commonly used, which eliminates damage to them when driving in the wedges that prevent the building from settling. The second type of insulating sheet used is fibreglass-reinforced polyester sheeting, which increases rigidity and makes it easier to insert into the gap, especially in stone walls. The choice of material depends on the type/structure of the wall and the cutting tools used.

Which walls can the PRINZ method be applied to?

The method works well both in walls with a regular pattern of horizontal joints — most often brick walls — and in mixed or stone walls, where wire saws are used for cutting. For cutting the walls of castles or churches, whose thickness exceeds 110cm, diamond wire saws are generally used.

Does the method require breaking the structural continuity of the wall?

The work is carried out in sections of limited length (a maximum of 1m), so that at every stage of the process the wall retains its load-bearing capacity. Subsequent wall sections are only cut once the previous ones have been stabilized and completed — by installing the insulating sheets and driving in the system wedges — so that the building’s structure does not lose stability during the process.

Is the PRINZ method safe for the building’s structure and statics?

Yes, the method is completely safe, provided it is carried out by professionals — certified PRINZ partners (list of companies available at the link). The work is carried out in stages — the wall is cut in short, roughly one-metre sections. Immediately after the insulating sheet is inserted, high-strength plastic wedges are driven into the gap, which take on the structural loads.

Is the building at risk of cracking or settling?

Thanks to the low linear speed of the cutting tools and slow cutting feed rates, no vibrations are generated during the work that could cause damage. Cutting in one-metre sections combined with proper wedging of the building completely prevents the walls from settling and does not cause them to crack. The static load resistance of the ABS wedges is 500 kg/cm² — on average five times more resistant to compression than brick. Furthermore, ABS does not deform under prolonged load (no creep effect), which is crucial for preventing wall settlement.

What warranty is given for the completed service?

After the horizontal insulation has been installed using the PRINZ method and the wall has naturally dried out, the problem of capillary damp will not return — most of our partner companies provide a 30-year warranty, and in practice the effect lasts for the entire technical lifespan of the building.

Is the PRINZ method 100% effective?

The PRINZ method is regarded as the most effective and most predictable method of secondary horizontal insulation, because it creates a physical, impermeable barrier — rather than relying on the “assumed” penetration of a preparation into the wall. However, its effectiveness depends on the work being carried out correctly and on the proper qualification of the building, which is why we always precede the implementation with thorough diagnostics. Correctly executed, it is 100% effective.

Is this a permanent or a temporary solution?

A correctly installed barrier made of plastic insulating sheets is permanent in nature — it is more durable than insulation installed at the construction stage of a new building. It does not lose its properties over time and does not undergo chemical or biological degradation.

After how long are the effects of wall drying visible?

The barrier itself starts working immediately after installation, cutting off the capillary supply of new moisture. However, the complete, spontaneous drying-out of a wall that has been damp for years is a gradual process — depending on the wall’s thickness, the type of material, and ventilation conditions, it can take anywhere from a few months to roughly a year. This process can be sped up by more than double through proper wall preparation, air dehumidifiers, circulation fans, and raised temperature, or specialist methods such as microwave drying.

How long does the work take on a typical 10x10m residential building?

The duration of the work depends on the length and thickness of the walls, the type of material they’re made of, their accessibility, and the complexity of the building. The strength of the PRINZ wall-drying technology lies in the speed and efficiency of the service — for an average wall thickness of 0.5m (total wall surface in the building of about 20m²), installing a new horizontal damp-proof insulation typically takes 3 working days.

Do you have to move out of the building during the work?

No — the building can continue to be used during the work, though this naturally comes with certain inconveniences. Work is carried out in sections and can be divided by room, which helps limit disruption for residents or users of the building.

Is the work disruptive — noise, dust, vibrations?

Cutting through the wall does involve a certain level of noise and dust, which is why we continuously protect the rooms. Vibrations transmitted to the structure are minimal, since the cutting is precise and controlled, and the equipment used runs at low speed. The wall is not crushed or chiseled out — it is “worn away” using special carbide chains or a diamond wire.

Does the method require intervention on the façade or inside the rooms?

Work is generally carried out from one side only — either the exterior or the interior of the building — depending on accessibility and the building’s construction. Access to the other side of the wall is, however, necessary in order to seal the cut working gap. In special cases, where the building has external insulation such as polystyrene or façade wool, no interference with the façade is required.

Does the building need to be specially prepared for the work?

The scope of preparation is determined on a case-by-case basis — it usually includes exposing a section of the wall along the cutting plane and protecting furniture and fittings in the immediate vicinity of the work. Free access to the wall is required — a strip about 2m wide on the side where the cutting is carried out, and about 0.7m on the other side of the wall. It may also be necessary to remove any plasterboard partitions.

Do we need to dry out the building before the service is performed?

Absolutely not. That’s one of the advantages of the PRINZ method. The degree of dampness in the walls has no effect whatsoever on the installation or effectiveness of the horizontal insulation. In fact, damp walls result in relatively less dust being generated during cutting.

Does the filling mortar need to be injected after every meter of insulated wall?

No, the mortar is injected at the end of the work into all the walls, under a pressure of about 5 bar. The building’s structural stability is maintained mainly by the system wedges. In special cases — where the walls are already in poor technical condition before work begins — the mortar is injected in stages, e.g. into each insulated wall section separately.

What type of walls qualify for the treatment?

Practically any type. The main difference lies in the equipment we need to use for the job and the cost of the service. However, in brick walls with regular horizontal joints (cut using carbide-tipped saw chains), the service is significantly cheaper compared to mixed and stone walls (cut using a diamond wire).

Can the method be used in historic buildings?

Yes, the mechanical method is in fact often recommended for historic buildings, because — unlike injection methods — it does not introduce foreign chemical substances into the structure of the historic wall and is easy to document for conservation purposes. The insulation materials used are insoluble in water and environmentally neutral, meaning they do not release any toxic substances into groundwater and do not react with building salts or the chemicals contained in the mortar injected after the insulation is installed. In every case, however, such work requires approval from the heritage conservator.

What are the limitations of the method — when is it not advisable or not possible to use it?

Carrying out the work can be difficult in stone walls made of fine-grained material, as well as in places where there is no access to both sides of the wall. In such cases, we look into the possibility of using alternative or combined methods.

Does wall thickness matter?

Yes — wall thickness affects the choice of tool, the horizontal damp-proof barrier material, and the duration of the work. The PRINZ method works well both in thin walls and in very thick historic walls, though this requires the use of appropriate equipment.

Is the method used only on external walls?

No, the horizontal barrier is installed in all load-bearing and partition walls exposed to rising capillary damp — both external and internal. If damp marks are visible in a building on only some of the walls, it’s generally advisable to install the new damp-proofing in all the walls. Very often the old horizontal insulation still works in part of the building’s walls, but after a short time, damp patches start to appear in those spots as well.