Nitocote SN511: Penetrating Silane Water Repellent Treatment

Product Overview

Nitocote SN511 (previously known as Emer-Stop S100N) is a deeply impregnating, isobutyltriethoxysilane-based water repellant and chloride ion protective treatment for concrete. It is a low viscosity colourless neutral liquid designed to protect concrete structures from both water and chloride ingress whilst still permitting water vapour transmission out of the structure. The product is especially suitable for protecting concrete structures in marine and coastal environments.

Key Features and Advantages

Nitocote SN511 provides a comprehensive range of protective benefits:

• Reduces water and chloride ingress - Significantly minimizes moisture and salt penetration
• Deep penetration into porous substrates - Achieves thorough protection through the concrete matrix
• Allows water vapour to escape from the structure - Maintains breathability while blocking liquid water
• Environmentally friendly - solvent free - Contains no organic solvents
• Exceptional alkali resistance - Resists alkaline degradation
• Reduces the effects of Alkali-Silica reactive aggregates - Mitigates ASR-related damage
• Increases freeze thaw resistance - Enhanced durability in freeze-thaw cycles
• Minimises efflorescence - Reduces salt bloom on surfaces
• Chemically resistant to ice melting compounds, fuels, oils and atmospheric contaminants - Provides broad chemical protection

Chemical Composition

Nitocote SN511 contains a >98% active content of monomeric isobutyltriethoxy silane, which is the primary protective agent. Due to its low rate of hydrolysis, this active ingredient penetrates deeply into porous substrates, reacting to produce a bonded hydrophobic lining to the pores. Being solvent free, the product is distributed with uniform high concentration practically throughout the entire penetrated area.

The product reacts chemically with the concrete to form a continuous hydrophobic (water-repelling) coating. This hydrophobic surface prevents the ingress of liquid water carrying chloride ions while allowing water vapour to escape.

Performance Properties

The following performance values are achieved when Nitocote SN511 is applied at the minimum recommended application rate:

Application Specifications

Application Method and Rate

Nitocote SN511 should be applied by saturation flooding working vertically from the bottom up. This is most easily achieved by:

• High volume, low pressure spray (approximately 5-10 psi), using an outlet diameter of 5mm in such a way as to minimize atomisation
• Simple direct application using a watering can or back pack spray for small areas
• Note: Nitocote SN511 must not be applied by brush

Coverage and Application Rate

For horizontal surfaces and soffit areas, the material should have a mirror-like wet look for 5 seconds. On vertical surfaces, a minimum rundown of 150mm must be visible with a mirror-like wet look for 5 seconds.

Wet Film Thickness Control

The product must remain in contact with concrete surfaces as a liquid film for a few seconds to achieve proper penetration. When spray applied, some loss due to atomisation is unavoidable owing to the high wetting effect and low viscosity; however, this is taken into account in the recommended application rate.

Surface Preparation

Surfaces must be thoroughly prepared before application:

• Dry and free from contamination - All surface contamination must be removed
• Free from oil, grease, loose particles, decayed matter, moss, algal growth, laitance - Complete cleaning required
• Free from all traces of mould oils and curing compounds - Critical for adhesion
• Plants, glass, asphalt, bitumen, plastics and all painted surfaces - Must be protected prior to application

Impregnation Depth

The impregnation depth achieved by Nitocote SN511 is influenced by several factors:

• Formulation characteristics
• Humidity conditions
• Concrete porosity
• Surface preparation level undertaken

In certain circumstances, the penetration will not reach the expected levels due to one or more of these factors. Fosroc recommends independent concrete core testing to confirm the actual penetration depth achieved.

Storage and Shelf Life

Nitocote SN511 has a shelf life of 3 years if kept in cool, dry conditions in the original, unopened packs. If stored at high temperatures and/or high humidity conditions, the shelf life may be reduced.

Material from Opened Containers

Material from opened containers must be used within 48 hours or discarded, as Nitocote SN511 may hydrolyse with atmospheric moisture.

Supply Formats

Cleaning and Removal

Nitocote SN511 should be removed from tools, equipment and mixers with Fosroc Solvent 10 immediately after use.

Alternative Primer Application

Nitocote SN511 is an alternative primer product that can be applied at the same coverage rate as Dekguard Primer to achieve 0.4 litres/m². It serves as an alternative primer to Dekguard Primer that can be applied before Dekguard S coating.

Limitations and Precautions

• Hydrolysis risk - May hydrolyse with atmospheric moisture; material from opened containers must be used within 48 hours
• Hydrostatic pressure - Hydrostatic pressure to concrete immersed at >300mm will force water molecules and dissolved chloride ions into the substrate through the silane
• Penetration variability - Impregnation depth is influenced by formulation, humidity, concrete porosity, and surface preparation level
• Tidal zone application - In tidal zones, application shall not commence until the tide has reached its lowest ebb, allowing the longest possible drying period before application

References

• [1] Fosroc_Nitocote_SN511_TDS.pdf
• [2] Fosroc_Nitocote_SN508_Creme_TDS.pdf
• [4] Fosroc_Nitocote_SN502_TDS.pdf
• [5] Fosroc_Nitoprime_DG_TDS.pdf