Dilute SILRES® BS 4004 US is an excellent water repellent for many absorbent mineral substrates, such as bricks, sand-lime brick, natural sandstone and mineral plasters. It is not so suitable for less absorbent, dense natural stone, especially limestone, marble and reinforced concrete for bridges and roads.
Owing to its aqueous consistency and storage stability when diluted, SILRES® BS 4004 US is ideal for in plant hydrophobation of building materials made of clay, aerated concrete, sand-lime brick, mineral fibers and lightweight aggregate.
SILRES® BS 4004 US may also serve as a water-repellent primer for emulsion paints and plasters, silicone resin emulsion paints and silicone resin plasters.
Processing as a Hydrophobic Impregnating Agent:
Tap water is suitable for preparing solutions of SILRES® BS 4004 US for use as facade water repellent primer. We ecommend an active substance content of 5-10% (dilute the product in the ratio 1:4 to 1:9), the exact figure depending on how absorbent the substrate is. Always homogenize the concentrate and also the diluted product before use (short mixing).
Apply the ready-to-use solution in the usual way preferred. Two "wet on wet" coats are needed to ensure complete coverage. If it starts to rain, stop treatment and cover the impregnated areas.
Processing as a Concrete Admixture (Water Resisting Admixture):
The recommended admixture range of a 1:4 dilution of SILRES® BS 4004 US is 1.0 % to 5.0 % of the cement content. A significant reduction in water uptake can already be achieved at a concentration of 1.0 % of the cement. SILRES® BS 4004 US is added either simultaneously with or immediately after the mixing water – it should never be added along with other additives. To keep a constant w/c value the total mixing water is reduced by amount required earlier for dilution. We recommend testing compatibility with other concrete admixtures separately. A longer mixing time will thoroughly distribute the product within the overall system, which in turn will make it highly effective.
When used in concrete goods or similar concrete products according to EN 1338, 1339 or EN 1340, an initial-type test (cf. section 6.2 of the respective standard) is recommended.
