Waterproofing Materials


BORNIT® 2K Flex (Thick Bitumencoating)

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BORNIT® 2K Flex (Thick Bitumencoating)
Highly flexible, 2-component, bituminous thick coat compliant with EN 15814 / DIN 18533, polystyrene filled, highly polymer-modified, for sealing buildings against moderate water under pressure, very good crack bridging, solvent-free, with general building authority test certificate, applicable up to layer thickness of 7 mm directly on solidly filled masonry possible, spray-on with the appropriate device, also suitable for adhesion of insulation board. Prime with BORNIT® Basement Primer. Tested radon tightness.
Protect against frost!
Color: black

4 017228 004426 6900002539 30 liters 18 buckets

approx. 4 - 6 liter/m² depending on water impact class
insulation board adhesion: approx. 2 liter/m²

tests / CE declaration of performance
LEISTUNGSERKLÄRUNG - gemäß Anhang III der Verordnung (EU) Nr. 305/2011
BORNIT® 2K Flex (Thick Bitumencoating) - 30 liters

detailed information


1023 / 0432
BORNIT-Werk Aschenborn GmbH
Reichenbacher Straße 117
D-08056 Zwickau
EN 15814: 2011 + A2: 2014
Kunstoffmodifizierte Bitumendickbeschichtung (PMB) zur Bauwerksabdichtung erdberührter Bauteile
Wasserdichtheit W2A
Rissüberbrückungsfähigkeit CB2
Beständigkeit gegen Wasser bestanden
Biegsamkeit bei niedrigeren Temperaturen bestanden
Maßhaltigkeit bei hohen Temperaturen bestanden
Brandverhalten Klasse E
Druckfestigkeit C2A
Dauerhaftigkeit der Wasserdichtheit und des Brandverhaltens erfüllt

Product Description
BORNIT® 2K Flex is a two-component, thixotrophic Thick Bitumencoating based upon a modified bitumen emulsion and a reaction powder. BORNIT® 2K Flex is filled with polystyrene and is solvent-free. Due to the powder component a faster drying will achieved. After drying the coating is watertight and resistant to pressure, but also flexible enough to cover flakes and cracks up to 2 mm in the base. Because of the low material weight it is particularly easy to applicate.  The product has been tested as per the current valid “Testing Principles for the Issuing of Construction Certification for Bitumen thick coatings” guideline.

General construction certificate number: P-2001-4-433/01

Areas of Application:
BORNIT® 2K Flex is excellent for the following uses:
- waterproofing as bituminous thick layer for the hydro-insulation of structures against ground dampness and non-pressure and pressure water and for the hydro-insulation of terraces and balconies (under the cement finish) against capillary action dampness and surface water.
- for gluing thermal insulation panels, such as protection against noise, heat and cold onto concrete, plaster, masonry and dry construction panels
- for the permanent, flexible and reliable sealing of surfaces
The thick coating can be used universally on all common mineral bases, such as concrete or masonry consisting of cement bricks, lime cement bricks, bricks or perforated blocks, as well as on surfaces with a plaster or cement finish.

Technical Data:
Type 2-component thick coating, polystyrene-filled
Base modified bitumen emulsion
Colour black
Density useable mixture: approx. 0.72 g /cm³
Consistency pasty, stable
Application trowel or suitable spraying equipment
Workable for about 1 hour at 20°C
Resistant to rain after 6 hours at 20°C
Hardening 2 or more days depending on humidity, temperature and layer thickness
Application temperature at least +5°C
Storage it must not freeze!
Storage period at least 12 months
Maximum layer thickness  up to 8 mm
Cleaning when fresh using water, after drying using BORNIT® Bitumen Stain Cleaner or BORNIT® MultiClean
Dangerous substances none

Surface preparation:
Step 1: The substrate must be free from ridges or sharp-edged unevennesses as well as soil.
Step 2: Unfilled or badly filled depressions like masonry joints, mortar pockets or  surface defects larger than 5 mm have to be repaired with suitable mortar. It is  not necessary to apply plaster to fully or well-pointed masonry. Voids smaller  than 5 mm as well as pores in the substrate can be closed by applying a thick  layer of bitumen coating in a scraping manner. Especially for concrete  surfaces, application in a scraping manner is recommended to avoid blistering.
Step 3: The substrate must be solid, clean, dust-free and free from any separating  substances. The substrate should be absorbent. It may be slightly damp, but  never wet.
Step 4: An undercoat with BORNIT®-Basement Primer or BORNIT®-Unibit (diluted  with water 1:2) is principally recommended. For very porous or highly  absorbent substrates (e.g. porous concrete), an undercoat is absolutely  necessary. For solidification of sandy substrates, priming with BORNIT®- Solidificator is recommended. Upon drying of the undercoat, the substrate is
prepared for application of  the thick coating.
Important: Thick bitumen coatings can be damaged during the construction phase by water affecting the backside of the layer. It has to be made sure in any case, that the coating is not damaged by water affecting the adhesive side. If necessary, water-impermeable intermediate layers of mineral waterproofing slurry (e.g. BORNIT®-Slurry SF, BORNIT®-Slurry EL) must be applied, which cannot be detached from the substrate by water pressure.

Application of thick coating Before beginning the work, the emulsion is mixed with a slow running mixing machine until it becomes liquid. The powder additive is added gradually. Both components are intensively mixed in the mixer until a homogeneous smooth substance is achieved (mixing time about 2 to 3 minutes). Component A and component B are supplied in the required amounts. At a temperature of 20°C, the material remains workable for about 1 hour. During extreme high summer temperatures, the reaction occurs more quickly. Application is carried out on the dried bonding primer by using a trowel.

Usually, the thick layer is applied in two working operations, because a uniform insulation layer is achieved during the two-layer application. The spreading of the filler over the entire surface using the serrated filling knife or smoothing trowel can represent the first layer. In the case of hydro-insulation against pressure water, two layers must be applied at an overall thickness (when wet) of at least 7 mm (consumption ca. 7 liter / m²).

The fresh layer must be protected from rain and direct sunshine.

BORNIT®-2K Flex may be used at a minimum air and base temperature of +5°C. Insulation panels may be affixed once the BORNIT®-2K Flex has completely dried. In principle, it is necessary to protect the bitumen insulation layer. Suitable protective layers consist of polystyrene foam panels, burled films and similar materials.
The filling up of the excavation may be carried out once the insulation layer has completely dried (after 3 or more days according to the climatic conditions).

Polymer modified bitumen coating (KMB) are in the current DIN 18195 for load cases "non-pressurized water - Heavy Duty" and "groundwater" is not listed. According to VOB, Section C, of DIN 18336 in this case the use of BORNIT ®-Flex 2C in the bill is to be agreed and the customer to refer to this deviation to DIN 18195.

• soil moisture in the load cases / no seepage water (DIN 18195-4) as well as non-pressurized water / moderate use (DIN 18195-5):
approximately 4.5 - 5.0 l per m²> wet film thickness 4.5 - 5.0 mm dry film thickness> 3.2 - 3.6 mm
• For the load cases seepage water (DIN 18195-6) / pressing water (groundwater, depth of immersion <3 m):
about 6.0 to 6.5 liters per square meter> wet film thickness from 6.0 to 6.5 mm dry film thickness> 4.3 - 4.6 mm
• Dämmplattenverklebung: 2 l / m²

Thickness control
According to current DIN 18195, Part 3 on design object must have a thickness control when fresh (wet film thickness) and a review of the state of a drying, in the pit mounted, reference sample (eg brick) are performed. When waterproofing according to DIN 18195 Part 5 and 6 the results of these tests must be documented.

Load according to DIN 18195 part 4 and 5: minimum dry film thickness of 3 mm
Load according to DIN 18195 Part 6: minimum dry film thickness: 4 mm

BORNIT® 2K Flex must be protected from frost!  It is necessary to avoid temperatures of +30°C and direct sunlight. Shelf life in unopened, original packaging is at least 6 months.

Health, safety and fire protection:
Safety advice: Do not empty into drains. Avoid contact with skin.

Only empty containers may be recycled. Residual product according to GCU ASN: 080410 (adhesives and sealants containing wastes other than those mentioned in 080409); powder component to AVV-ASN: 170101 (concrete)..

30 liter combi bucket....................18 buckets each pallet


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Stock Note
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Necessary information – particularly for the use and the use of our products – please refer our brochures. We are at your personal disposal.