Dekguard Elastic: Elastomeric Protective Coating for Concrete and Masonry

Overview

Dekguard Elastic is a crack-accommodating elastomeric, pigmented acrylic protective coating system designed to protect concrete and masonry substrates from environmental degradation and corrosive agents. As a water-based coating, it is formulated to provide comprehensive protection against chloride ion attack, carbonation, and atmospheric exposure while accommodating substrate movement and minor cracking.

Key Uses and Applications

Dekguard Elastic is specifically engineered to protect atmospherically exposed, non-trafficked reinforced concrete structures from attack by:

• Acid gases - atmospheric corrosive contaminants
• Chloride ions - particularly critical in coastal and marine environments
• Oxygen - atmospheric element requiring protective barriers
• Water - moisture penetration and ingress
• Carbonation - chemical degradation of concrete

The coating system is equally suitable for application to new and existing structures, including those in coastal and marine environments. It is also appropriate for protecting cementitious substrates and masonry surfaces.

Technical Specifications

System Composition

The Dekguard Elastic system comprises two complementary components:

1. Nitoprime DG - A single-component penetrating silane-siloxane primer (supplied as a clear liquid)
2. Dekguard Elastic - A single-component elastomeric pigmented coating (water-based)

Both components are ready for immediate site use.

Application Rates and Coverage

Parameter	Specification
Dekguard Elastic Coverage	1.25 m² per litre (total 2 coats) / 0.4 litres/m² each coat
Nitoprime DG Coverage	2.5 m² per litre (total)
Theoretical Application Rate	0.4 litres/m² at 20°C ambient temperature

Film Thickness Requirements

• Total Dry Film Thickness: Not less than 400 microns when applied in two coats
• Wet Film Thickness: Not less than 400 microns per coat
• Application in two coats is essential to achieve correct protective properties

Performance Properties

Test Method	Typical Result
Volume Solids	49%
Elongation at Break	>400% (ASTM D412)
Carbon Dioxide Diffusion Resistance (R)	>150 metres
Equivalent Thickness of 30 MPa Concrete Cover (Sc)	>380 mm
CO₂ Diffusion Coefficient	3.8 × 10⁻⁰⁷ cm²/sec
Water Vapour Transmission Rate	40.4 g/m²/24hr
Equivalent Thickness of Air (Sd)	<1 m
Chloride Ion Diffusion Coefficient	5.5 × 10⁻¹⁴ m²/sec @147 days
Tear Resistance	12 N/mm² (ASTM D624-84)
Fire Rating	Class 1 (BS 476, Pt 7: 1987)

Crack Accommodation Capabilities

Dekguard Elastic can accommodate:

• Static crack spanning: Up to 8 mm at 400 microns dry film thickness at 20°C
• Dynamic crack bridging: 0-1 mm cyclic movement with 20,000 cycles at 20°C without failure
• Substrate cracking: Up to 6 mm with cyclic movement up to 1 mm

Key Advantages

• True elastomeric coating with excellent elongation and recovery properties maintained at sub-zero temperatures
• Excellent barrier protection to carbon dioxide, chloride ions, oxygen, and water
• Special acrylic polymer minimizes dirt retention
• Water vapour permeable - allows water vapour to escape from the structure
• UV-resistant with high resistance to long-term weathering effects
• Water-based formulation - environmentally friendly application
• Accommodation of substrate movement - maintains protective integrity during structural shifts

Product Availability and Supply

Dekguard Elastic is supplied in the following variants and container sizes:

Product Variant	Product Code	Container Size
Dekguard Elastic White	FC860600-15L	15 litres
Dekguard Elastic Special Colour	FC860621-15L	15 litres
Dekguard Elastic In Can Tint	FC860633-15L	15 litres
Nitoprime DG (Primer)	FC862600-20L	20 litres
Fosroc Solvent 10 (Cleaning Agent)	FC600800-4L	4 litres
Fosroc Solvent 10 (Cleaning Agent)	FC600800-20L	20 litres

Application Instructions Summary

Surface Preparation

All surfaces must be dry and free from contamination including:

• Oil, grease, and loose particles
• Decayed matter, moss, and algal growth
• Laitance and curing compounds
• Mould release oils

Lightly grit-blasting the surface is the recommended and best method to achieve the dry, contaminant-free conditions required before applying Dekguard Elastic.

Primer Application

Nitoprime DG must be applied first as a primer flood coat at the coverage rate of 0.4 litres/m² (2.5 m²/litre). The primer should be allowed to dry for a minimum of 2 hours at 20°C before application of the coating.

Coating Application

Dekguard Elastic is applied in two coats, each achieving a wet film thickness of not less than 400 microns. The coating can be applied by:

• Spray application - on well-prepared surfaces without blowholes, providing substantial time savings
• Suitable brushes
• Rollers

Environmental Restrictions

• Application should not commence if substrate temperature is below 5°C
• Do not apply where frost exposure is likely within 48 hours of application
• Avoid windy conditions where dust adhesion may occur
• Avoid application where rain is likely within 2 hours at 20°C or 20 hours at 5°C
• Do not apply when relative humidity exceeds 90%

Cleaning and Maintenance

Dekguard Elastic should be removed from tools and equipment with clean water immediately after use.

Substrate Compatibility

Concrete Substrates

Dekguard Elastic is formulated for application to:

• Clean, sound concrete surfaces
• Atmospherically exposed reinforced concrete structures
• Concrete in coastal and marine environments

Masonry Substrates

Dekguard Elastic is formulated for application to:

• Clean, sound masonry surfaces
• Cementitious substrates
• Brickwork and blockwork

Limitations

• Not suitable for trafficable surfaces - designed for non-trafficked applications only
• Not for ponded water areas - Dekguard S should be considered for occasional ponded water exposure
• Application over existing coatings requires compatibility trials to ensure bond retention

Storage and Shelf Life

• Store in cool, dry conditions
• Protect from frost during storage
• Store in original, unopened containers
• Reduced shelf life at high temperatures

Manufacturer Information

Dekguard Elastic is manufactured and sold under license from Fosroc International Limited. The Dekguard trademark is owned by Fosroc International Limited and used under license.

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References

• [1] Fosroc_Dekguard_Elastic_TDS.pdf
• [2] Fosroc_Dekguard_E2000_TDS.pdf
• [3] Fosroc_Dekguard_S_TDS.pdf
• [4] Fosroc_Nitoprime_DG_TDS.pdf
• [5] Fosroc_Dekguard_Primer_TDS.pdf