How to Use Epoxy Coatings for Concrete Structures

Table of Contents

Concrete Deterioration

Concrete structures are naturally porous, which can make them vulnerable in demanding industrial environments. Frequent traffic, chemical exposure, moisture and mechanical wear can gradually damage concrete surfaces, leading to deterioration over time. In areas such as industrial floors, chemical containment areas, sumps, plinths, and machinery bases, this deterioration can affect cleanliness, safety, maintenance requirements, and asset reliability.

Protecting Concrete with Epoxy Coatings

To help protect concrete surfaces, many asset owners use epoxy coating systems. These coatings can provide a durable barrier against selected chemicals, moisture, abrasion, and traffic-related wear. When combined with suitable aggregates, they can also create a textured surface finish to improve grip on industrial floors and walkways.

Damaged concrete columns in a cooling tower, later rebuilt and protected with epoxy coating for concrete

What is an Epoxy Coating for Concrete?

Epoxy coatings for concrete are protective coating systems formed by the chemical reaction between base and solidifier components. Once cured, they create a durable barrier on suitably prepared concrete surfaces, making them ideal for areas such as industrial floors, chemical containment areas, concrete sumps, tank bases, and machinery bases subject to chemical spillage.

Epoxy coatings for concrete are usually designed to provide protection against:

Chemical or process media: Epoxy coating systems can provide durable protection for concrete surfaces exposed to a wide range of acids, alkalis, oils, solvents, and other process chemicals.

Intermittent moisture: These coatings can help protect concrete surfaces from moisture exposure by forming a durable protective barrier, helping to extend maintenance intervals in wet, wash-down, or periodically damp service areas.

Traffic, wear, and slip resistance: These coatings can help protect concrete surfaces against wear, abrasion, and chemical or moisture exposure. When combined with selected aggregates, they can also improve positive grip and slip resistance in areas exposed to pedestrian or vehicular traffic, such as industrial floors, walkways, workshops, and truck loading or unloading zones.

Epoxy coatings created a protective barrier against chemicals, environmental, and physical damage and also serving as positive grip flooring when combined with appropriate aggregates — Epoxy coatings create a protective barrier against chemicals, environmental, and physical damage and also serving as positive grip flooring when combined with appropriate aggregates

How to Apply Epoxy Coating for Concrete

This blog provides a step-by-step guide how to apply an epoxy coating to concrete using Belzona 5811 (Immersion Grade).

Belzona 5811 (Immersion Grade) is a 100% solids coating designed to protect concrete and other substrates exposed to immersion. Asset owners can apply the material by either brush or spray, making it suitable for both large and small spaces. This epoxy coating can resist chemicals such as ethanol, sulphuric acid, hydrochloric acid, potassium hydroxide, and crude oil.

Belzona 5811 (Immersion Grade), a sprayable epoxy coating for concrete

When tested in accordance with ISO 2812-2 and NACE TM 0174-Procedure B, the coating shows no blistering, rusting, cracking, or delamination after 6 months of immersion in seawater at 50˚C (122˚F).

Step 1: Surface Preparation and Cleaning before an Epoxy Coating Application

Mark the areas requiring epoxy coatings with masking tape. Remove all paint, tar, or any other existing coatings, loose surface material, grease, oil, dust, and laitance before the application of an epoxy coating. Ensure any new concrete cures for a minimum of 28 days before applying an epoxy coating or strictly follow the manufacturer’s instructions.

Remove all contaminants from the target concrete surface requiring epoxy coatings

Where damaged concrete is first repaired using compatible Belzona concrete repair materials, Belzona 5811 (Immersion Grade) can be applied as part of a complete Belzona repair and protection system. This allows concrete surfaces to be rebuilt and then protected against chemical and moisture exposure. For more information about the concrete repair using Belzona rebuilding magmas, visit the Top 5 Epoxy Concrete Repair Applications blog.

Step 2: Mix the Belzona 5811 (Immersion Grade) Base

Mix the base thoroughly using a mechanical mixer to reincorporate any settled materials.

Mix the base of Belzona 5811 (Immersion Grade) until the contents are fully combined — Mix the base of Belzona 5811 (Immersion Grade) to achieve a uniform color

Step 3: Combine Belzona 5811 (Immersion Grade) Base and Solidifier

Mix the Belzona 5811 (Immersion Grade) base and solidifier. For full unit mixing, gradually pour the solidifier into the base and use a mechanical mixer to combine the base and solidifier to achieve a uniform color, free of streakiness. For smaller repair areas, a partial mix is recommended using 3:1 by volume or 5:1 by weight. If the material temperature is below 10˚C, warm the base and solidifier container until the contents reach 20-25˚C (66-77˚F). For full details, please refer to the Instructions for Use.

Gradually pour the solidifier into the base and mix until a uniform color is achieved — Gradually pour the solidifier into the base and mix to achieve a uniform color

Step 4: Application of Belzona 5811 (Immersion Grade)

Belzona 5811 (Immersion Grade) is suitable for both brush and spray applications. Belzona recommends applying this material as a two-coat system.

Brush Application: Pour the fully mixed Belzona 5811 (Immersion Grade) onto the prepared concrete surface and spread it evenly with a rubber squeegee.

Pour the fully mixed material onto the target concrete surface

Finish by working the material into the surface using a short-bristled brush or a lint-free 6 mm NAP white woven roller. The recommended thickness of the first coat is 250 μm (10 mil). As soon as possible after application of the first coat, apply a further coat of Belzona 5811, preferably of contrasting color. Refer to the Information for Use Sheet for overcoating times. The target thickness of the second coat is 250 μm (10 mil).

Use a brush to apply the first coat until the thickness of 250 μm is achieved — Apply the first coat until it reaches a thickness of 250 μm

Spray Application: Heated-airless spray equipment may be used for the application of Belzona 5811 (Immersion Grade). Either a single airless or plural equipment are recommended. Note that the mixing should commence only when the equipment has been assembled and tested. For full details, please refer to the Instructions for Use.

In pedestrian traffic areas where slip resistance is required, Belzona grip system aggregates can be broadcast into the Belzona 5811 (Immersion Grade) immediately after application.

The installation of Belzona 5811 (Immersion Grade), an epoxy coating for concrete, mixed with appropriate aggregates, provides positive grip flooring to a walkway

Videos: How to Apply Epoxy Coating on Concrete Using Belzona 5811 (Immersion Grade)

How to mix Belzona 5811 (Immersion Grade)

Frequently Asked Questions

Can I use epoxy coatings for concrete in drinking water tanks?

Yes, you can use epoxy coatings in drinking water tanks, provided that the selected coating has the appropriate approval for contact with drinking water and that you apply it in accordance with the relevant approval scope and application requirements. Examples of relevant approvals include WRAS, AWQC, ACS, and NSF/ANSI 61.

For example, Belzona 5811DW2 (DW Immersion Grade) is a WRAS and ACS-approved material, suitable for water contact. Belzona 5812DW holds AWQC and NSF/ANSI 61 approvals, suitable for use in contact with drinking water.

Can I use epoxy coatings for concrete in areas subject to aggressive chemical media?

Yes, epoxy coatings can protect concrete against harsh chemicals, but the coatings must be selected based on operating conditions, such as:

Types of chemicals and their concentration
Exposure frequency
Service temperatures
Equipment or structure substrates

For example, product such as Belzona 5811 (Immersion Grade) provide protection to equipment subject to immersion conditions and demanding chemical environments. Belzona solutions demonstrate excellent resistance to a wide range of chemicals, for detailed information refer to the chemical resistance chart.

How can I select aggregates to create positive grip flooring on concrete substrates?

To form positive grip flooring and abrasion resistance on concrete, broadcast suitable aggregates to the wet coating. The selected aggregates help create a durable, textured floor finish with improved grip and abrasion resistance. The choice of aggregate type and particle size depends on the required surface profile and service conditions. Belzona also offers a range of aggregates including:

Belzona 9211 (Supergrip Aggregate): Particle size around 1.2 – 1.0 mm (16 – 18 grit/mesh), suitable for heavy-duty applications
Belzona 9221 (Surefoot Aggregate White): Particle size around 0.6 – 0.4 mm (30 – 40 grit/mesh)
Belzona 9231 (Surefoot Aggregate Grey): Particle size around 0.6 – 0.4 mm (30 – 40 grit/mesh)
Belzona 9241DW (Quartz): Particle size around 0.075 – 0.600 mm with NSF/ANSI 61 certified, suitable for application in conjunction with Belzona 5812DW for potable water contact

In addition to Belzona aggregates, asset owners may select locally available aggregates for use with epoxy coatings.

Where can I buy epoxy coatings for concrete?

Belzona epoxy coatings for concrete are available for purchase through a network of authorized Distributors in more than 120 countries worldwide. You can contact the Distributors directly through the Belzona Distributor Finder. The Belzona Authorised Distributors are not only able to provide Belzona materials but also onsite training and ongoing technical support.