Surface Retarder for Exposed Aggregate Concrete, 5 Gallon

Surface Retarder for Exposed Aggregate Concrete, 5 Gallon

Exposed Aggregate Concrete: Using Retarder, 5 Gallon

The Exposed Aggregate Retarder is for those who want to create decorative exposed aggregate finishes. This product is to be sprayed on one coat to retard the mortar set time so you don’t have to sandblast, acid wash, or use acid etching, avoiding costly sandblasting as well.

Easy to apply with standard pressurized spray equipment, brush or roller. Bon Tool 32-302 Exposed Aggregate Retarder is a concrete surface retarder for creating decorative exposed aggregate finishes on horizontal surfaces. Leaves no surface finish so it’s a natural, seamless look and feel. To keep your concrete looking its best, use a cement cleaning solution designed for tough stains and maintenance.

Covers 100 sq.ft. per gallon. Low VOC formula. Environmentally friendly and low odor compared to other products on the market.

Exposed Aggregate Retarder comes in 5 gallon container. Perfect for larger projects and less frequent restocking. For DIY homeowners looking to update their outdoor space or professional landscapers and contractors to offer their clients a high quality and cost effective solution for exposed aggregate finishes.

In short the Exposed Aggregate Retarder is a must have for anyone wanting to create beautiful outdoor spaces without the big bucks. Easy to apply, low VOC and covers 100 sq.ft. per gallon.

Exposed aggregate concrete is a popular choice for outdoor surfaces because of its durability, beauty and slip resistance. Exposed concrete is a type of washed concrete finish that features visible aggregates like pebbles, rocks and sand, with exposing aggregate being the key technique used to achieve this look. The process is used to expose aggregate in the concrete, creating a unique and textured finish. Other methods, such as abrasive blasting, can also be used to expose aggregate, but surface retarders are preferred for safety and control. In this article we will go over the benefits, design and installation of exposed aggregate concrete and how to maintain and seal the surface.

What is Exposed Aggregate Concrete?

Exposed aggregate concrete is a decorative concrete that involves exposing the aggregate (pebbles) in the concrete. Decorative aggregate is chosen for its beauty so you can have a unique and artistic finish. This is done by removing the top layer of cement paste, which is typically the retarded mortar when using a surface retarder, to reveal the aggregate underneath, creating a textured and slip resistant surface. Surface retarders allow for controlled depth of exposure by chemically inhibiting hydration to a specific depth, ensuring the underlying concrete cures properly. It is important to check a small area to confirm the desired level of aggregate exposure has been reached before completing the process. Exposed aggregate concrete can be made with various types of aggregate such as crushed stone, shells, pebbles, decomposed granite, recycled glass, quartzite, salt rocks, basalt and limestone.

Benefits of Aggregate Concrete

Exposed concrete has several advantages over regular concrete surfaces. It's durable and long lasting, wear and tear resistant and has a unique and textured finish. The exposed surface is also good traction and slip resistant making it a safe choice for outdoor surfaces. Exposed concrete is low maintenance, only needs occasional sealing to maintain its appearance.

Design and Installation

Design and installation of exposed concrete involves several steps. First the area is prepared by laying down a layer of compacted gravel or sand. You need to have prior experience in mixing cement and laying concrete to achieve the desired result. Then a layer of concrete is poured and screeded to create a smooth surface. At this stage, finishing techniques are important, as they impact the final appearance and the depth of exposure. The aggregate is then seeded onto the surface of the fresh concrete or green concrete, and the concrete is troweled smooth to create a flat finish. The surface is then allowed to firm up before exposing the aggregate.

Exposed finishes are commonly used on concrete slabs and poured in place flatwork for decorative and durable surfaces. Using a concrete retarder is applied to the fresh concrete after initial finishing, which helps with surface mortar set eliminating, reducing the need for abrasive cleaning methods like sandblasting or acid washing. Exposed pavers have advantages over poured concrete such as versatility and low maintenance. While poured concrete has its merits, it lacks the flexibility of aggregate such as being able to replace or move individual pavers.

Using a Surface Retarder

A retarder is a chemical additive that slows down the setting of the concrete, giving you more time to work with the material. Surface retarders work by delaying the setting of the surface layer of fresh concrete, allowing easier removal of the surface mortar while the underlying concrete sets and cures normally. When working with exposed concrete, using a retarder is especially beneficial. It gives you more working time to lay, finish and expose the aggregate at a more controlled pace. This is especially useful for larger projects or in warmer climates where concrete sets quickly.

One of the biggest benefits of using a concrete retarder is the finish it can achieve. By slowing down the setting process, you can get a more even and consistent exposure of the aggregate, resulting in a beautiful textured and visually appealing surface. Additionally, retarders allow the underlying concrete to harden properly, ensuring strength and durability. This extra exposure can make a big difference in the overall look of your project.

However, use concrete retarders carefully. Over retardation can weaken the concrete structure and compromise its durability and longevity. There is also a higher risk of cracking if the concrete is not properly cured. To avoid these problems, always follow the manufacturer’s instruction for dosage and application. Before full application, it is recommended to use a test area to determine coverage and assess the retarder’s effect, ensuring the desired surface finish. Monitor the concrete’s setting process and adjust the retarder dosage as needed. Regular testing can also ensure that the concrete meets the required strength and durability standards.

By using a retarder properly you can get a high quality exposed aggregate finish that is durable and visually appealing.

Suitability and Compatibility of Retarder

When choosing a concrete surface retarder, it’s important to consider both the type of project and the specific conditions of your site. Concrete surface retarders are best suited for use on horizontal concrete surfaces such as floor slabs, patios, and precast panels. These products are designed to slow the setting time of the surface mortar, allowing for controlled exposure on freshly placed concrete.

Surface retarders are not recommended for vertical concrete surfaces, as they may not adhere properly or provide uniform results. Additionally, avoid using a surface retarder on existing concrete or on surfaces that have been treated with shake-on color hardeners, as this can interfere with the desired finish and the performance of the retarder.Compatibility with your concrete mix design is also important. Some surface retarders may alter the setting time or strength gain of the concrete, so always check that the product is suitable for your specific mix. Don’t use surface retarders on concrete containing calcium chloride or other set accelerators as these additives can affect the performance of the retarder.

Environmental conditions such as temperature and humidity can affect how the retarder performs. Always follow the manufacturer’s instructions for application based on the current weather and site conditions for best results on your concrete surfaces.

How to Apply the Retarder

Applying a concrete surface retarder is a straightforward process but attention to detail is key for a consistent, decorative aggregate finish. Here’s how to do it:

1. Prepare the Surface: Make sure the surface is fresh and green, no bleed water present. Timing is critical—apply the retarder after finishing operations but before the surface mortar sets.

2. Apply the Retarder: Use standard pressurized spray equipment or a low pressure sprayer, hold the nozzle 12-18 inches from the surface. Spray the retarder evenly, don’t puddle or over spray.

3. Ensure Uniform Coverage: For best results use a stiff broom or garden hose to gently spread the retarder and ensure it covers the entire surface uniformly. This will give you a consistent exposure depth across the slab.

4. Allow to Work: Let the surface retarder work for 12-24 hours depending on the product and environmental conditions. This controlled delay in the hydration process will allow the surface paste to remain soft while the concrete hardens properly.

5. Expose the Aggregate: Once the retarder has done its job, remove the surface paste using a pressure washer or garden hose. Work carefully to avoid damaging the concrete and to get a uniform depth of exposure.

6. Clean Up: Follow all recommended cleaning procedures to remove any residue and prevent environmental hazards.

Always read the manufacturer’s instructions and adjust your process as needed based on the weather and your concrete mix. Proper application will give you a beautiful, durable aggregate finish on your horizontal concrete surfaces.

Precautions and Safety Measures

Working with concrete surface retarders requires careful attention to safety and environmental best practices. Here are some important precautions to follow:

• Wear Protective Gear: Always wear gloves, safety glasses and a mask when handling surface retarders to protect your skin, eyes and respiratory system.

• Mind the Weather: Don’t apply the retarder in windy or rainy conditions as this can cause uneven application or runoff, environmental hazards and inconsistent results.

• Protect Adjacent Surfaces: Keep the retarder away from adjacent masonry, reinforcing steel and other surfaces that could be damaged by the chemicals. Use plastic sheeting or other barriers if necessary.

• Avoid Chemical Interference: Don’t apply curing compounds or other chemical methods to the surface before or after using the retarder as this can affect the performance and final appearance of the aggregate.

• Test First: Always do a test patch on a small, inconspicuous area of the surface. This will help you determine the optimal application rate, removal time and ensure the retarder works as expected for your specific project.

• Proper Disposal: Follow all local regulations for cleaning procedures and disposal of leftover product and materials to minimize environmental hazards.

• General Safety: Keep the work area well-ventilated and store unopened containers of retarder safely out of reach of children and pets.

By following these safety measures and precautions you can confidently use surface retarders to get high quality aggregate finishes while protecting yourself, your project and the environment.

Concrete Sealer

To maintain the appearance and durability of exposed concrete it is recommended to apply a concrete sealer. A concrete sealer protects the surface from stains and damage and can also enhance the color and texture of the aggregate. There are several types of concrete sealers available, fully matte, high gloss and everything in between. Choose a sealer that is specifically designed for exposed concrete and follow the manufacturer’s instruction for application.

Exposed concrete patio is cost effective in the long run due to its non slip texture and durability. This type of patio can withstand heavy foot traffic and harsh weather, making it a long lasting option for outdoor spaces.

Maintenance and Upkeep

Maintaining exposed concrete is important to preserve its appearance and extend its life. Regular maintenance will ensure your surface will remain attractive and functional for years to come. Here are some tips to keep your exposed concrete in top shape:

• Cleaning: Clean the surface with mild detergent and water to remove dirt, debris and stains. A pressure washer can be used for deep cleaning but use it on low setting to avoid damaging the surface layer.

• Sealing: Sealing is important to protect the surface from stains, damage and weathering. Choose a sealer for exposed concrete and follow the manufacturer’s instruction for application. Sealing will enhance the color and texture of the aggregate and provide a protective layer against the elements.

• Inspections: Inspect the surface for damage, cracking or wear and tear. Early detection will allow for prompt repair and prevent further deterioration and concrete integrity

• Repairs: Repair any damage or cracks as soon as possible to prevent them from getting worse. Small cracks can be repaired with concrete patching compound, while bigger damage may require professional help.

By following these maintenance and upkeep tips you can keep your exposed concrete looking beautiful and durable and safe and attractive for your outdoor spaces.

Cost and Budget

The cost of exposed concrete will vary depending on the type of aggregate, concrete mix and labor cost. Here are the average cost:

• Material Cost: $8 to $12 per square foot. This includes the cost of aggregate, concrete mix and any other materials needed for the project.

• Labor Cost: $2 to $5 per square foot. Labor cost will vary depending on the complexity of the project and the contractor’s experience.

• Total Cost: $10 to $17 per square foot. This is a rough estimate and will vary depending on location, project size and other factors.

When budgeting for your exposed concrete project consider the following costs:

• Materials: Aggregate, concrete mix and other concrete materials.

• Labor: Laying, finishing and exposing the aggregate.

• Equipment: Rental or purchase of equipment, pressure washer and concrete saw

• Maintenance: Maintenance and upkeep cost to keep the concrete looking good and long lasting.

For a more accurate estimate contact a professional contractor or supplier. They can give you a detailed breakdown of the cost and help you plan your budget.

Comparison with Other Finishes

Exposed concrete is a unique and decorative finish that has several advantages over other finishes. Here’s a comparison to help you understand the benefits of exposed concrete:

• Stamped Concrete: Stamped concrete can look like stone or brick but aggregate concrete has a more textured and visually appealing surface. The natural look of the aggregate has a rustic charm that stamped concrete doesn’t.

• Polished Concrete: Polished concrete is smooth and modern. Exposed concrete is natural and earthy. The exposed pebbles and stones create a unique texture that adds character to any outdoor space.

• Standard Concrete: Standard concrete is functional but lacks the decorative appeal of exposed concrete. Exposed concrete has a more durable and visually interesting finish that’s why it’s a popular choice for patios, driveways and walkways.

When choosing a finish:

• Aesthetics: Exposed concrete has a unique and decorative finish that can add visual appeal to your outdoor spaces.

• Durability: Exposed concrete is durable and long lasting, perfect for high traffic areas.

• Maintenance: Exposed concrete requires maintenance but it’s worth it for the beautiful and durable finish.

Now you know the differences.