General Information


The investor and the contractor, commencing a new investment, must face numerous difficulties of the construction process. More often than not, decisions made at an initial stage reflect at a further stage of the structure's use. An important role in the usage and aesthetics of a structure is water-resistant insulation. One should not take lightly work related to sealing and insulation.
At such a key point of the construction process, investment in high-quality materials is worthwhile. In the least advantageous situations, where one should care for the tightness and seal of structures under threat of water under pressure, the only effective material that can be used is heavy water insulation. Doubtless, one of the most effective insulation materials available on the market are bentonite-halloysite mats of the Bentizol series.
The Bentizol type HB3 and HB5 bentonite-halloysite mineral mats are a combination of layers of geofabric and geotextile, made of highly resistant polypropylene fibre, joined together through needle gunning. A mix of sodium bentonite and halloysite is found between then.
Bentonite is a loam, the name of which comes from the first excavated deposit at Fort Benton in the state of Wyoming, USA. Bentonite is a component of the active insulation system. In contact with water, it swells up to a multiple of its initial size, maintaining its low hydraulic conductivity. In this regard, however, one needs to keep in mind an appropriate compression layer, ensuring the maintenance of a high pressure value caused by the substance increasing its volume.
The created bentonite gel will pass very thoroughly into the concrete's porous structure, sealing possible leakage points of water and creating an impenetrable barrier. Sodium bentonite locked between the fabrics is able to appropriately bind the water, blocking out its ways of escape. Bentonite is able to lose its insulation properties under the influence of calcium and magnesium ions. It works properly across a relatively small range with a pH value of approx. 7.
Adding halloysite to the mix turned out to be a very novel step. Halloysite is resistant to chemical influences, particularly by magnesium ions, occurring at every construction site in the form of ground water and stemming from construction materials. Such a fusion of sodium bentonite and halloysite amplifies their mutual positive properties resulting in unlimited possibilities of use of the compound created as universal insulation over a broad range of pH values (4-9) in any environment.
Bentizol bentonite-halloysite mineral mats are effective heavy insulation for all structures located in areas with unfavourable soil and water conditions. They protect against the destructive phenomenon of penetration of reinforced concrete components and corrosion of reinforcement steel. In a proper protection system for an underground structure part it is important to appropriately protect all day joints emerged during concreting and expansion joints, beside the execution of a humidity and water insulation system. The Bentizol mineral mat does not create independent structure insulation in these areas.

Stage 1 Stage 2
Stage 3

Bentizol bentonite-halloysite mineral mat
Package Sales unit
Weight [kg]
Art. no.
52,50 m² /roll
52,50 m²

105,00m² /roll
105,00 m²

31,50 m²

Bentonite-halloysite granulate (3)
10,00 kg/bag
10,00 kg kg
Bentonite-halloysite granulate (3) -
15,00 kg/bag
15,00 kg
Bentonite-halloysite granulate (3) -
25,00 kg/bag
25,00 kg

(1) Pallet dimensions: 2,10 x 1,20 m.
(2) Retail unit.
(3) For each Bentizol mat order, a bentonite-halloysite granulate mix is delivered in the following amounts:

  • for mat rolls of L = 15 r. m., one bag with granulate of 10 kg is supplied,
  • for mat rolls of L = 25 r. m., one bag with granulate of 15 kg is supplied,
  • for mat rolls of L = 50 r. m., two bags with granulate of 15 kg or three bags of granulate of 10 kg are supplied.




Bentizol bentonite-halloysite mineral mat

The rolls of bentonite-halloysite BENTIZOL mineral mats are used for effective execution of heavy surface insulation in reinforced concrete structures subject to influence of humidity and water under pressure.
The mat roll's large area ensures quick installation. Ease in execution of insulation limits the possibility of errors during installation to an absolute minimum.
For every executed order of mats, a bentonite-halloysite granulate mix, necessary for the overlay work, is supplied.






Bentonite-halloysite granulate

An innovative mix of sodium bentonite and halloysite, also making up a mat's fill material, used as additional binder for joints as well as packing and face material at key spots of the structure to be insulated.
The putty is prepared by mixing the granulate with water at a weight ratio of 1:3.







Parameter Unit
Bentonite-halloysite mineral mat Norm / test method
Mat condition
Surfaces without damage; mat sides protected against the filler mix escaping out Visual evaluation
Thickness under load of 2 kPa
5,0 ± 20%
7,0 ± 20%
PN-EN ISO 9863-1
Mass per area unit
3 000 ± 15%
5 400 ± 15%
PN-EN ISO 9864
Filler volume per 1 sq m of mat g
2 700 ± 15%
5 100 ± 15%
ZUAT – 15/IV.10
Tensile strength Lengthwise
≥ 6,0
≥ 7,0
PN-EN ISO 10319
≥ 3,0
≥ 3,0
Relative extension at maximum load Lengthwise %
≤ 17
≤ 18
PN-EN ISO 10319
≤ 10
≤ 10
Water permeability (liquid insulation) m³/m² ·s
≤ 9,0 · 10-9
≤ 5,5 ·10-9 ASTM D 5887-95
Permeability Ψ at 10 °C s-1 ≤ 5,0 · 10-9 ≤ 3,0 · 10-9 -
kv mat filtration coefficient m/s
≤ 5,0 · 10-11 ≤ 3,0 · 10-11 ZUAT – 15/IV.10
Static puncture (CBR) test kN
≥ 1,2
≥ 1,2
PN-EN ISO 12236
Swell coefficient ml/2g
≥ 21
≥ 21
Reaction to fire klasa
PE-EN 13501-1
Durability Oxidation resistance -
Maintained resistance (after 28 days) exceeds 50% of initial tensile strength for a lifetime of 25 years prEN ISO 13438
Textile and fabric chemical resistance -
Maintained resistance (after 56 days) exceeds 50% of initial tensile strength EN 14414
Influence of wetting and drying cycles on met permeability

Permeability Ψ at 10 °C s-1 ≤ 6,0 · 10-9 ≤ 3,2 · 10-9 prEN 14417
qi stream (at 21 °C) m³/m² ·s ≤ 11,0 · 10-9 ≤ 6,0 · 10-9 prEN 14417
R factor %
prEN 14417
Influence of freezing and thawing cycles on met permeability Permeability Ψ at 10 °C s-1 ≤ 5,0 · 10-9 ≤ 5,0 · 10-9 prEN 14418
qi stream (at 21 °C) m³/m² ·s ≤ 10,0 · 10-9 ≤ 9,0 · 10-9 prEN 14418
R factor %
prEN 14418

Bentizol bentonite-halloysite mineral mat filler mix parameters:

Trials according to
Montmorillonite content %
68 ÷ 70
Halloysite content
18 ÷ 18
Humidity after 24 h free swelling
≥ 500
Enometric swell factor %
≥ 150
Free swell factor (2 g / 100 ml / 24 h) cm³
≥ 16
Swell pressure kPa
≥ 200


Advantages of the Bentizol bentonite-halloysite mineral mat as heavy insulation

Doubtless, among the advantages of the Bentizol mat should be included its ability of self-repair of its damage. A puncture of an installed and tensioned mat surface shall not cause any failure of the insulation system, because the bentonite gel created in the swelling process will thoroughly fill the construction component.
The installation of the mat in formwork before concreting positively influences the joint of the fabric and the concrete poured in situ. This improves the bond between both components and protects the surface insulation against damage when executing foundation packing. At times, when everyone is so caring of he environment, it is noteworthy that our product is 100% natural, and may be used without any reservations.


Bentizol bentonite-halloysite mineral mats form impenetrable barriers for liquids in underground tunnels and structures. Installing the mats on panels and foundation walls is very effective.
The mats may also be used to seal foundation slabs and footing strips. Bentizol mats are used directly on fixed foundation excavation structures, at the same time fulfilling the role of stay-in-place formwork (i. e. Berliner walls, concrete stockades, steel partitions made of Larssen sheet piles).
Bentonite-halloysite mineral mats may be used as insulation of underground liquid refuse structures, intermediary stations or secondary stations as well as protective housings in sewage treatment plants. They are also used as protective means for landfills and solid waste storage areas.
They constitute heavy insulation in hydrotechnical engineering structures such as i. e. water tanks and dams. They have been successfully used as insulation of structures related to water control and as water barriers in dykes and polders or in artificial water bodies.

The Bentizol bentonite-halloysite mineral mats may be used broadly in the geotechnical industry to make insulation partitions. They may be used as insulation for:

  •  water structures:

- overflow dykes,
- polders,
- natural fire water bodies,
- land irrigation ditches and linear road drainage,

  • buildings:

- underground building structures,
- foundation slabs,
- warehouses,
- diaphragm walls,

  •  structures:

- underground tunnels,
- sewage treatment plant storage tanks,
- landfills.



The execution of heavy insulation using bentonite-halloysite mats may be commenced with surface preparation work. The soil substructure for mat installation should be fairly even, free of stones, rubble, roots and any sharp objects so that the arranged mat will adhere to the entire soil surface. It must be appropriately resistant and stable, uniformly packed so that traffic by construction machinery during layout of the mats would not cause surface deformations. The Bentizol mineral mat may be laid out on a lean concrete layer, on formwork or on an executed reinforced concrete structure.

Making overlays and joints







The bentonite-halloysite mineral mat rolls laid out should be joined with overlaying. Beginning the installation of a subsequent roll, the edges of the neighbouring mats should lie on top of each other along a length of 15 cm - 30 cm. In addition, the overlays of ends of the neighbouring bands should be shifted with respect to each other by 30 cm.
In order to avoid leaks at joints of subsequent rolls, the surfaces of the overlays should be cleaned and evened out, to ensure direct adherence of the joined bands, and then covered with the bentonite-halloysite granulate according to a minimum ratio of 0,5 kg/r. m. The mat should be fixed to the subsurface by nails or staples directly through the fabric, and each such joint should be processed with bentonite putty.


Installation in foundation slabs and at low points

During the execution of insulation for future placement of foundation slabs, it is recommended to lay out the mats on a base concrete layer. The mats should not be placed in pits and at low points filled with water or snow. If, however, slab concrete pouring is planned at a much later time than a mat is laid out, the mat needs to be protected from adverse weather conditions. An optimum solution is using a compression layer of lean concrete that will additionally protect the mats against mechanical damage during concreting and carpentry work. The mat must be laid out with its darker side (the fabric) towards the reinforced concrete structure. In case of concreting of a foundation slab in stages, one needs to remember to leave a free mat area outside of the outline of the executed slab with a minimum width of 30 cm. The thus created day joint must be additionally protected against water intrusions. For the execution of expansion slits, it is recommended to add another band of the mat with a length of one metre symmetrically along the slit. The fixing of Bentizol mats on foundation slabs with extensive low points should start with insulating the low points. The mat should be laid out from top to bottom. It should not be thrown from great heights. The remaining loose mat ends at the elevation of the slab's underside should be anchored so that they do not slip away under their own weight. All piping (i. e. passages of the water lines) or metal components (i. e. earthing, temporary steel pillars) passing through the structure protected by the Bentizol mineral mat should be protected against water intrusions by trimming the mat to fit the shape of the part and by executing face layers of the putty made of the bentonite-halloysite granulate.Should this prove necessary, they should be protected against water intrusions using the FORBENT swell tape or a different equivalent solution. The joint should be tightly packed with bentonite-halloysite granulate or the bentonite-halloysite putty from the underside and the top side.
The putty is prepared by mixing the granulate with water at a weight ratio of 3:1. In certain situations, passages of installations should be reinforced by patches cut out from additional pieces of the bentonite-halloysite mat. All joints must be generously packed with bentonite-halloysite putty.

Step 1. Unrolling the mat on a previously prepared surface and execution of the joint overlays. Step 2. Execution of insulation at foundation slab low points.
Step 3. Execution of side faces and rolling the mat away on the foundation wall. Step 4. Detail of execution of side face of bentonite-halloysite putty in a concave structure corner.


Installation on vertical walls and Larssen sheet piles

The execution of water insulation of foundation walls requires more engagement in the executed work, however the general rules remain the same. The installation difficulty may be posed by the execution of the bentonite subsurface layer at the mat overlay points, and hence, it is recommended that an elastic mass of bentonite-halloysite granulate be created to putty up the overlays. Similar steps need to be taken at the ends of the mat insulation layer areas.
The rolled-out mat needs to be fixed to the wall using nails, with the free end tightly covered with bentonite putty. In case of insulation of external walls with varying shapes, all concave corners should be rounded out through the creation of facets of bentonite-halloysite granulate putty.
The installation of the bentonite mat on foundation walls needs to conclude approx. 30 cm below the ground layer. Mat insulations should be joined to become permanent along the entire surface of the foundation walls, so that they continue to above the surrounding soil layer with the use of bitumen film or insulation. The thermal insulation layers of polystyrene need not be anchored through Bentizol mat insulation. If it should become necessary to insulate the bolt passages, bentonite putty needs to be designed and laid out at these locations. A different solution might be laying out the mat on styrofoam.
Styrofoam panels must be made vertical using bentonite-halloysite granulate putty, to eliminate all slits. Before the end fragment of the mat insulation under ground, it must be affixed by staple gun directly to the concrete structure. In case of installation of bentonite-halloysite mineral mats on Larssen sheet piles, one of two methods needs to be used.
To optimise mat usage, the Larssen pile may be covered with OSBs with the insulation executed directly on them. A different solution is installing the mat on the Larssen sheet pile, this method, however, increases consumption. In case of installation of Bentizol mats on concrete stockades, adherence of the mat to the entire wall surface must be ensured to be as good as possible.

Installation on vertical walls

Step 1. Pulling the mat onto the foundation wall and execution of the joint with the insulation prepared on the slab. Step 2. Mat insulation needs to end 30 cm below surface level (mat ends need to be turned over and affixed to the wall with nails.
Step 3. Rounding of concave corners with bentonite-halloysite putty. Step 4. Additional insulation of outside and inside corners of the foundation slab.
Step 5. Additional insulation of pipe passages. Step 6. Conclusion of mat cover insulation.


  • Installation on Larssen sheet piles.
Step 1. Layout of the mat on bottom slab surrounded by Larssen sheet piles. Step 2. Execution of edge at mat ends along Larssen piles.
Step 3a. Extending the mat vertically to cover the Larssen piles. Step 3b. Execution of formwork along partitions and installation of mat on the ready formwork.


The Bentizol bentonite-halloysite mineral mats of types HB3 and HB5, manufactured to individual customer orders, may be shipped in various sizes, and, depending on the mat area in the roll, may vary greatly in mass.
The standard width of a Bentizol mat roll is 2,1 m, and the length is 15 m for the HB5 type mat, and 25 m for the HB3 type mat.

At the construction site, an appropriate place of storage of Bentizol mats needs to be prepared. The pallets with the material need to be stored at a side, at a spot that is evened out and dry, with appropriate access guaranteed from all sides to facilitate unloading. Storage needs to be limited at the construction site to the absolute minimum. The mat needs to be protected against humidity and sunlight. The rolls and the granulate need to be covered with additional water-resistant material or hidden under a roof of any kind. The roll packaging should not be removed until exactly the time of installation.


Bentizol mats need to be transported by road vehicles with appropriately long trailers, so that entire rolls fit inside the trailer's outline. Uncontrolled bending and extensions may tear apart the needle joint of the outside layers. During transport of Bentizol bentonite-halloysite mineral mats, one needs to take care for the transport to take place in a manner protecting them from harmful atmospheric conditions and mechanical damage. During loading and unloading, mechanical equipment, such as forklifts, cranes, excavators, is recommended. The transport and storage of bentonite mat rolls is allowed in up to five layers.