Elastic waterproofing membrane IMPELAST

Preparation of surfaces:

Remove flaking, friable or non-adhering parts, paints, rust, dust and release agents. All surfaces to be treated must be solid, clean and dry. Surfaces with irregularities, very rough plaster and castings, holes, gravel pockets, cracks etc. must be repaired and/or smoothed. Check the soundness and efficiency of water flow points (waste water). Treat or assess in advance any expansion joints: carry out prior sealing of control and insulation joints using the PU 40+ structural adhesive and sealant product. Before sealing, insert backfill material acting as a "third wall" at the bottom of the joint. Where necessary, according to the degree of moisture of the surface, prepare appropriate condensation outlets. Any critical points, or where the product is highly mechanically stressed, should be reinforced with non-woven fabric 130 g/m² (joints, connections with vertical components etc.) or elastic bands, as needed, inserted between two layers of IMPELAST. The product is normally ready to use. When used as primer, it can be mixed with water, either by hand or with a mechanical mixer at low speed

Cement surfaces:

Treat the surface with primer composed of IMPELAST diluted to 50% with water (2 parts IMPELAST to 1 part water) at 300 g/m². In the case of pre-stressed concrete or porous materials (e.g. tuff), prepare the surface with B4 primer. In the case of damp and absorbent supports, use BK10 PRIMER at 150–300 g/m² in accordance with absorption by the surface

Bituminous surfaces:

Flaking bituminous surfaces must first be restored. Self-protected bituminous membranes with slate shavings must be pre-treated with primer composed of IMPELAST diluted to 50% with water at 300 g/m². On non-self-protecting surfaces, apply B4 primer at approximately 120 ml/m². Then apply IMPELAST after no less than 4 hours and no more than 24 hours. For white Impelast, use of BK10 PRIMER at approximately 150 g/m^² is recommended in order to avoid oil potentially seeping from the recently installed bituminous membranes

Tiled surfaces:

On non-absorbent ceramic surfaces, apply C20 A primer at approximately 250 g/m². For absorbent surfaces, apply B4 primer at approximately 250 ml/m² depending on the porosity of the surface

Metal surfaces:

Surfaces affected by rust, after thorough cleaning and repair of damaged parts, must be pre-treated with Rust Converter. Then apply Rust-Stop primer or another suitable primer. On aluminium surfaces, start with light sanding, then clean, degrease and pre-treat with C20 primer, approximately 200 g/m²

Wood surfaces:

Pre-treat wood surfaces with B4 primer, approximately 250 ml/m². If the wood is painted and in an excellent condition, light sanding and subsequent cleaning is sufficient before applying the primer

After thoroughly preparing the surfaces, apply the first layer of IMPELAST at 1 kg/m² using a roller, brush or airless sprayer. Wait until fully dry, then apply the second coat, approximately 1 kg/m². We recommend applying the layers in contrasting colours so to make distributing the product easier

For floors made of pre-stressed reinforced concrete slabs, follow these steps:

• Pre-treat the surface with B4 primer


• Seal the structural joints with PU 40+ structural adhesive and sealant and filler material. (See the "Preparation of surfaces" section)


• Carry out the IMPELAST treatment with non-woven fabric reinforcement

Waterproofing with non-woven fabric reinforcement:

• Adequately prepare the surface (see "Preparation of surfaces" section, then refer to the type of surface to be treated)


• Apply the first coat of IMPELAST at 1 kg/m² undiluted or slightly diluted with water (max. 5%) using a roller, brush or airless sprayer


• Overlap new non-woven fabric by 100 cm, ensuring that it is well impregnated and taking care not to leave bubbles or air pockets. Overlap the different geotextile layers by at least 10 cm


• When dry, apply a second coat of undiluted IMPELAST at 1–1.2 kg/m². Be sure to overlap the waterproofing material by about 10–20 cm with vertical components at the joints

Type A, visible outside (Validation report no. 250697 by the Giordano Institute)

• 1) After cleaning the surfaces, apply a coat of B4 primer at between 200–300 ml/m²


• 2) When dry, apply a first coat of IMPELAST at 400–500 g/m²


• 3) When completely dry, apply a second coat of IMPELAST, which must be in a contrasting colour to the previous coat, at 400–500 g/m2

Type B, visible inside (Validation report no. 258004 by the Giordano Institute)

Type C, not visible, as a support for formwork (Validation report no. 258005 by the Giordano Institute)

• 1) After cleaning the surfaces, apply a coat of IMPELAST diluted with water (ratio 1:1) at between 200–300 g/m²


• 2) When dry (after approximately four hours), apply a first coat of IMPELAST at 400–500 g/m²


• 3) When completely dry, apply a second coat of IMPELAST, which must be in a contrasting colour to the previous coat, at 400–500 g/m²

Type D, for removal procedures (Validation report no. 250700 by the Giordano Institute)

After cleaning the surfaces, apply IMPELAST at 250 g/m² diluted at 35% with water