Formulation of a ready-to-use solution
The product should be diluted before application.
Most of the time, the weight dilution ratios are 1:10 to 1:20 and depend on the substrate and its absorption capacity.

Surface preparation
Only vertical surfaces or surfaces with a steep slope are concerned by this type of treatment.


The surfaces must be:
Dry: After rain, wait for at least 24 hours, or after cleaning of the surface with pressurized water, wait for 3 days (in dry weather).
Sound: Brush off parts with low adherence (on crumbly, powdery or encrusted surfaces), fill cracks of more than 0.3 mm and clean stained surfaces.
In all cases, avoid cleaning with acidic or alkaline chemical detergents
Windows should be protected before application of the product.

Application method

  • With a flat brush on very rough materials or with a roller (reserved for small surfaces)
  • By flooding under low pressure or with an airless spray gun with a variable spray nozzle.

  • Whatever the application method, the product must be applied until the surface is saturated, without insisting. The glossy appearance should not remain.
  • Most of the time, a single coat is enough to have the performances
  • A one liter solution of BLUESIL BP 9400 may be sufficient to treat a surface of 3m², but this quantity may vary since it essentially depends on the type of substrate and its absorption capacity (from 0.2 to 2 liters per m² depending on the substrates).

- mortar, concrete 0.3 to 0.5 l/m²
- sand stones 0.4 to 0.6 l/m²
- lime stones 0.4 to 2 l/m²
- mineral plaster 0.6 to 0.8 l/m²
- brick 0.6 to 1.2 l/m²
  • Optimal waterproofing performances of the materials treated will only be obtained if a sufficient quantity of BLUESIL BP 9400 is applied.

It is essential to carry out a preliminary test on the surface to be treated. 
BLUESIL BP 9400 may be stored for up to 18 months from its date of manufacturing.Please consult the Safety Data Sheet of this product.


BLUESIL BP 9400 is a solventless alkylpolysiloxane oligomer designed to protect facades against moisture.
BLUESIL BP 9400 is dilutable with organic solvents.
After it has dried on the surface, BLUESIL BP 9400 repels water and allows walls to breathe.
BLUESIL BP 9400 can be used as impregnating agent and/or as primer.

Additive;Breathability;Coating;Hydrophobing;Primer;Protection;UV resistant;Water Repellency


Impregnation with BLUESIL BP 9400 provides long-lasting limitation of the water penetration in the walls and facades without blocking their breathability (water vapor exchanges).
BLUESIL BP 9400 has been specifically designed to have the following properties:

  • quick drying on all neutral and alkaline substrates : the beading effect is noticeable within a few hours after application
  • high water penetration resistance by capillary action.
  • versatility allowing its use on many mineral materials
  • very good vapour permeability
  • non film forming, very slight change in the material’s natural porosity and aspect
  • outstanding resistance to ageing agents (freeze, thaw, uv, etc.) due to the stable structure of the siloxane bonds that form with the substrate’s reactive groups.

Experience acquired over more than 40 years shows that silicone water repellents are a good answer to humidity problems in construction materials, particularly when for esthetical reasons the natural aspect of the material should be preserved. 

Asia Pacific;Europe Middle East Africa;Central and South America;North America




Viscosity< 1000Monocompmm2/s




































Solutions for building protection for building protection