BORNIT® Water Stop (SM2)

building waterproofing | basement waterproofing | system module | cementitious
short information
  • highly reactive powder
  • extremely short initial setting time (within a few seconds)
  • for sealing flow points
  • cement-based mortar
  • weathering, de-icing salt and frost-resistant
Water Stop SM2 (system-modul 2)
15 kg / bucket
sufficient for:
EAN code
euro pallet
approx. 10 m²
4 017228 00432 7
36 bucket
approx. 1.0 - 2.0 kg/m²
storage note
  • dry, in closed containers
  • storable for 12 months in the original sealed container

status technical data sheet
09 December 2020

areas of application
BORNIT® Water Stop (SM2) is used for extremely fast and permanent closure of leakages and water infiltration in concrete, masonry and natural stone structures on the negative side, if waterproofing from the outside (positive side) is not possible.
Contact with water causes an extremely quick catalytic reaction, which immediately stops the flow of water.
BORNIT® Water Stop (SM2) is used for waterproofing of leakages and sealing of water-bearing cracks in basements, tunnels, underground parking garages as well as concrete components of reservoirs, sewage systems, floodgates or water tanks.
The product can also be used for immediate fixation of natural stones in hydraulic structures and for stopping leaks in stoneware pipes or annular joints in shafts.

type and properties
BORNIT® Water Stop (SM2) is a highly reactive, cement-bonded plugging mortar, setting within seconds after contact with water. After setting, the product is permanently water-impermeable as well as resistant to weathering, de-icing salt and frost.

  • Using this system, leaky surfaces and individual spots are waterproofed in a quick and simple manner, even with the water flowing. The success is immediately visible. Waterproofing is undertaken on the negative side, i.e. against the water pressure.
  • Using this system, the following effects are combined:
  • 1. Spot waterproofing against pressing, flowing water.
  • 2. Surface waterproofing against pressing, flowing water.
  • 3. Silicification of the waterproofing layer and the leaky construction material, such that this is compacted and becomes part of the waterproofing.
  • 4. The waterproofing is permanent, since it becomes a fixed component of the building structure.
  • 5. Easy, secure processing and cost-effective.

A stable, firm and clean substrate is the prerequisite for permanent secure waterproofing. Paints and also plasters, which contain lime (also hydraulic lime), screeds, etc., must be removed down to the solid construction material (masonry/concrete). If possible, scrape out joints in the masonry down to approx. 2 mm.
Pre-moisten dry surfaces well multiple times prior to starting application. Holes and open joints should be filled with BORNIT® Sealing Mortar.

Prior to applying the BORNIT® Basement Coating System to aerated concrete, lightweight and heavy concrete blocks (e.g. Poroton), a stable plaster layer of BORNIT® Sealing Mortar must be applied.
Unsuitable substrates:
- Limy plasters
- Paint coats and coatings
- Gypsum-based construction materials

All substrates must be stable, firm, absorbent and free from dust and gypsum. Remove loose particles as well as residues of bitumen, oils, greases, dust or separating layers of any kind. Active leaks have to be pried open down to the stable substrate and widened conically.

Depending on the application, there are various processing options when using BORNIT® Water Stop (SM2). In principle, non-profile rubber gloves must be worn upon processing! Processing can be undertaken from +5 °C to approx. +25 °C. Observe the substrate and water temperatures!

Waterproofing of leaks
A sufficient quantity of dry BORNIT® Water Stop (SM2) is taken up by hand and then quickly and with force pressed onto the leak until the water has been stopped.

In case of water infiltrating as a jet or with high pressure, quickly mix BORNIT® Water Stop (SM2) with cold water (mixing time approx. 15 seconds) into a thick paste, form it into a ball-shaped plug and press it into the leak, until the water infiltration has been stopped (approx. 40 seconds). The speed of hardening largely depends on the quantity of water admixed (reference value at +20 °C: approx. 250 g of water for 1 kg of BORNIT® Water Stop (SM2)). After admixture, hardening sets in after approx. 30 seconds. Longer waiting periods result in “burning” of the material, i.e., it becomes crumbly and there is no proper hardening.

Use as System Component 2 in the BORNIT® Basement Coating System, inside
Within the BORNIT® Basement Coating System, inside (observe the respective technical datasheet!), BORNIT® Water Stop (SM2) is used as System Component 2 for quick drying of BORNIT® Slurry (SB1) as a dry powder over the entire surface.

Subsequent work
Following elimination of the leakages using BORNIT® Water Stop (SM2), normally surface waterproofing of the soaked substrates or walls, resp., must be undertaken. For that, use the BORNIT® Basement Coating System, inside or BORNIT® Slurry EL.

waterproofing of leakages, water infiltration: as needed

product data in brief
product type
highly reactive powder with an extremely short setting time
Portland cement
density at +20 °C
approx 3.00 g/cm³
manually, with smooth rubber gloves
The devices must be cleaned with clean water immediately after use.
dry, in closed containers
shelf life
storable for 12 months in the original sealed container
GISCODE link comp. A
hazard class according to ADR
Melting point
+1250 °C
Bulk density
1.16 kg/m³

health and fire protection, occupational safety
To ensure safe handling of the product, the physical, safety, toxicological and ecological information provided online, the information in the current safety data sheet and the additional information on the label must be read and followed before purchasing or using the product! The applicable regulations, ordinances and laws must be complied with.

In case of doubt, please contact the BORNIT® application technology department or the BORNIT® service hotline on +49 375 2795 123.

Store dry and cool. Can be stored for approx. 12 months in tightly closed original packaging.

disposal note
Only recycle completely empty containers. Material residues can be disposed of according to AVV-ASN: 101303 (waste from the production of other cement-based composites).

The above information replaces all previous technical information about the product. Thus, this information is no longer valid. The details have been compiled according to the latest state of application technology. Please observe, however, that, depending on the state of the construction object, deviations from the method of application suggested in the datasheet may be required. Unless agreed otherwise in individual contracts, any information contained in the datasheet shall be non-binding and thus does not represent an agreed product constitution. We reserve the right to any changes in the information contained in this datasheet anytime.
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UFI MG40-G0NQ-T004-75JD

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-     What: name of the substance or product as precisely as possible, etc.
-     How much: as exact a quantity as possible
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component A


Kein Gefahrgut im Sinne der Transportvorschriften.

Hazard pictograms

signal word

Hazard-determining components for labelling
Portlandzementklinker; Calciumoxid

recommended, personal protective equipment:

component B

H315: Causes skin irritation.
H318: Causes serious eye damage.
H335: May cause respiratory irritation.

P101: If medical advice is needed, have product container or label at hand.
P102: Keep out of reach of children.
P280: Wear protective gloves/protective clothing/eye protection/face protection/hearing protection.
P305 + P351 + P338: IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
P310: Immediately call a doctor.
P501: Dispose of contents/container to a suitable recycling or disposal facility.