Waterproofing of basements against moisture and water without hydrostatic pressure

RELATED MATERIALS

AQUAMAT Cement-based waterproofing slurry

DUROCRET Polymer-modified cement mortar

RAPICRET Fast-setting patching mortar

ADIPLAST Polymer latex for multiple improvements of mortars

PLASTIPROOF Plasticizing/water reducing admixture for concrete

 

I. NATURE OF THE PROBLEM – REQUIREMENTS

Basement areas must be effectively waterproofed against moisture and water in order to be usable. Where the problem is simply moisture or water without hydrostatic pressure (e.g. penetration by rain water), then the waterproofing layer to be applied should be:

  • Efficient against moisture or water.

  • Long lasting, especially because of the difficulties in access and permanent contact with soil.

II. SOLUTION

Wherever possible, it is recommended that the waterproofing layer is applied on the external side of the basement shell, which is the side from which water penetrates.

Coating the exterior basement walls and the interior floor (the only feasible solution) with AQUAMAT cement-based, brushable sealing slurry, creates a waterproof layer that:

  • Offers effective waterproofing.

  • It is vapour permeable and ensures the viability and utilisation ability of the basement area.

  • It is characterised by reliability and longevity due to the inorganic nature of the material.

Ιf exterior coating is not feasible, AQUAMAT can alternatively be used in the interior, since it bonds strongly to the substrate and withstands negative pressure.

In case of a new building, it is also recommended that PLASTIPROOF concrete waterproofing admixture is added during concreting the structural elements of the basement in a proportion of 0,2-0,5% by cement weight.

III. APPLICATION

Substrate preparation

  1. The substrate should be thoroughly cleaned from any possible formwork oil residues, loose particles, dust etc.

  2. Any cavities in the concrete should be cleaned from loose particles, aggregates etc.

  3. Form wires and distancepiecesshould be cut at a 3 cm depth.

  4. Any working joints should be widened in a V-shape along their length, at a depth of 3 cm.

  5. The surface of the above areas should be thoroughly dampened and filled with DUROCRET polymer modified cement mortar, or with a cement mortar reinforced with ADIPLAST polymer latex. Alternatively, when fast work is necessary, RAPICRET fast-setting patching mortar can be used instead.
    DUROCRET consumption: 25 kg for trearing a 30-40 m2 surface (indicative consumption for a normal concrete wall).

  6. Intersections of the floor with vertical elements (concrete walls, columns), should be dampened and sealed, along their entire length with DUROCRET polymer modified cement mortar, or with a cement mortar reinforced with ADIPLAST polymer latex (formation of a “groove” with a triangular cross-section having 5-6 cm sides).
    DUROCRET consumption: 1,9-2,7 kg/m of “groove”.

  7. All surfaces should be thoroughly dampened, without creating standing water.

AQUAMAT application

  1. The contents of one bag of AQUAMAT (25 kg) is gradually added into 8,25 litres of water under continuous stirring until a uniform slurry, suitable for coating, is formed. A low-revolution (300 rpm) mixer can be used for mixing.

  2. 2-3 layers of AQUAMAT are applied on the external walls of the basement. The coating surface must extend at least 50 cm above ground level. Each layer must be fully dry before the next one is applied. To avoid cracking, each layer should not be more than 1 mm thick.
    Consumption: 2-3 kg/m2 in total.

  3. 2-3 layers of AQUAMAT are applied on the basement floor. Each layer must be fully dry before the next one is applied. The floor coating must extend on the concrete walls or columns at least 50 cm above the groove formed at the intersection with the floor. To avoid cracking, each layer should not be more than 1 mm thick.
    Consumption: 2-3 kg/m2 in total.

  4. It is recommended that the AQUAMAT layer on the basement floor is protected against possible damage by a protective layer (cement screed, tiles etc.).

IV. REMARKS

  • The ambient temperature during application of the material must be above +50C.

  • The AQUAMAT layer must be protected from high temperature, rain and frost.

  • AQUAMAT contains cement and reacts as alkaline with water, so it is classified as irritant.

  • Consult the usage risks and safety advice written on the bag.

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