Waterproofing is applied to both walls and floors of damp and wet rooms as essential for their long-term usability. It is important to ensure substrates remain dry and free from water damage particularly as many grouting materials are not waterproof nor do they offer if waterproof sufficient protection from water ingress. Substrates on which the waterproofing system is applied should under normal circumstances withstand stresses caused by the movement of the building, being exposed to water and temperature fluctuations, and the alkalinity of concrete and mortar.

The water exposure classes can be classified as follows:

  • Low exposure (W0-I): It includes low areas with infrequent exposure to water spray such as (1) wall surfaces above sinks in bathrooms and sinks in domestic kitchens, and (2) floor areas in homes without drainages such as kitchens, utility rooms, and guest toilets.
  • Moderate exposure (W1-i): It includes areas frequently exposed to water spray or infrequent exposure to service water, without intensification due to ponding water such as (1) wall surfaces above bathtubs in showers and bathrooms, (2) floor areas in the home with a drain and (3) floor areas in bathrooms with or without a drain without high water impact from the shower area.
  • High exposure (W2-I): It includes areas with frequent exposure to spray water and/or industrial water especially on the floor, occasionally intensified by ponding water such as (1) wall surfaces of showers in sports facilities / commercial facilities, (2) floor areas with drains and/or gutters, (3) floor areas in rooms with floor-level showers, and (4) wall or floor surfaces of sports facilities / commercial sites.
  • Very high exposure (W3-I): It includes (very high exposure) includes areas with very frequent exposure to splash water and/or industrial water and/or water from intensive cleaning processes intensified by ponding water such as (1) areas in the vicinity of swimming pools, (2) areas of showers and shower facilities in sports facilities / commercial sites, and (3) areas in commercial sites (commercial kitchens, laundries, breweries, etc.).

Crack classes substrates encountered for typical membrane substrates include the following:

  • R1-I: for maximum changes in crack width up to approx. 0.2 mm on reinforced concrete, masonry, screed, plaster/render, structurally continuous, and sealed joints in gypsum board/gypsum fiberboard linings.
  • R2-I: for maximum changes in crack width up to approx. 0.5 mm on joints in large-format blockwork masonry, structurally continuous joints in panel claddings/linings.
  • R3-I: for maximum changes in crack width up to approx. 1.0 mm, plus offset between crack faces up to approx. 0.5 mm on wall base joints.

Recommended damp and wet room waterproofing solutions stand as follows:

  • For W0-I to W2-I: crack bridging class R0-I to R3-I apply a cold self-adhesive bitumen geo-membrane with High-Density Polyethylene in one layer.
  • For W0-I to W3-I: crack bridging class R0-I to R3-I apply a cold self-adhesive bitumen geomembrane with High-Density Polyethylene in two layers.


  • For W0-I to W2-I: on walls, for crack bridging class R1-I, apply a polymer dispersion in 0.5 mm thickness minimum.
  • For W0-I to W1-I: on floors, for crack bridging class R1-I, apply a polymer dispersion in 0.5 mm thickness minimum.
  • For W0-I to W3-I: on floors and on walls, for crack bridging class R1-I, apply a crack-bridging mineral waterproofing slurry in 2mm thickness minimum.

More details pertaining to the requirements for design and execution and waterproofing materials can be found in DIN 18 534 "Waterproofing for indoor applications" that took effect in July 2017.

Related Products:

Batimix HWR 1500
BATIMIX HWR 1500 is a high-performance liquid high-range water-reducing (superplasticizer) admixture for concrete. It is based on synthetic polycarboxylate acid derivatives and on carefully selected chemicals.
Batimix Mortar W-800
BATIMIX Mortar W-800 is a surface-applied cementitious-based material, which waterproofs and protects concrete in-depth. It is made from Portland cement, carefully-graded sand, and a combination of selected additives, including water-reducers, surfactants, anti-foams, emulsifiers, water-repellents, and crystallization chemicals. When applied to carefully prepared substrates, the active chemicals of BATIMIX Mortar W-800 react with the free lime and moisture present in the capillary pores of the concrete to form insoluble crystalline complexes. The so-formed crystals block the capillaries and minor cracks to prevent any further water ingress. BATIMIX Mortar W-800 allows the passage of water vapor through the concrete. It can thus be applied against active and passive water pressure surfaces.
Batimix Mortar W-860
BATIMIX Mortar W-860 is a cementitious non-shrink and waterproof grout used for filling joints smaller than 4mm. It is made from Portland cement, carefully-graded sand, and a combination of selected additives to enhance workability, adhesion, and waterproofing. It is durable, resistant to frost and heat after setting.
Batimix Sealer L-880
BATIMIX Sealer L-880 is a liquid silicate-based dispersion used as a surface concrete floor hardener. It is recommended for both interior and exterior use.

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Important Note: Holderchem shall have the right to modify product specification sheets at any time without previous notice. Buyers should always refer to the most recent data sheets, copies of which can be supplied upon request. The sale of products mentioned in this literature shall be subject to Holderchem’s General Conditions of Sale Delivery and Payment[Visit: https://holderchem.net/gcsdp]

Holderchem R&D
Holderchem R&D seeks to develop solutions to meet construction challenges by bringing to market innovative products and systems, which offer benefits across the complete life cycle of buildings and other constructions. The aim is to supply customers with high-performance products to help them achieve better productivity, lower overall costs, and achieve extended service life and functionality. Research also aims at developing the Holderchem range of Batimix products with a particular focus on polymer emulsions, polymer-inorganic interactions, and product applications.
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