Course Description

In this video, we show how to install Indiana Limestone pavers onto an existing concrete slab using a permeable, bonded paving system. This 4-component set of products, when used together, forms a bonded construction system with an incredible permeability rating. The system is based on a polymer-modified Trass Bed cement that possesses superior bonding strength. The result is a fully permeable paving system that contributes to sustainability and environmental objectives in landscape construction while still providing a long-lasting, load bearing surface.

How to Install Limestone Pavers on a Permeable, Bonded Paving System: Innovation Meets Tradition

The construction industry continually evolves, balancing time-tested methods with groundbreaking innovations that solve modern challenges. Permeable paving systems represent one such advancement, addressing environmental concerns while delivering superior performance. This installation method combines the best of both worlds: the durability of bonded construction with the environmental benefits of water permeability.

In this comprehensive guide, we’ll explore installing Polycor’s Indiana Limestone pavers using a revolutionary permeable bonded paving system that’s changing how professionals approach sustainable hardscaping projects.

Understanding Permeable Bonded Systems

Traditional paver installation typically forces a choice between permeability and structural integrity. Loose-set systems allow water penetration but may sacrifice stability, while rigid mortared installations provide strength but create impermeable surfaces that contribute to stormwater runoff problems.

Permeable bonded systems eliminate this compromise through innovative materials science. These systems create fully permeable surfaces that allow natural water infiltration while providing the structural integrity of traditional bonded construction. The result addresses both environmental sustainability and long-term performance requirements in a single solution.

The ROMEX System: German Engineering Excellence

The system demonstrated here utilizes products developed by ROMEX, a German company renowned for extensive research and development in construction materials. Through rigorous testing, they’ve created a comprehensive system of four complementary products that work together to form a superior bonded construction system for permeable pavers.

System Components

ROMPOX – TRASS BED COMPOUND serves as the foundation binding agent, utilizing trass minerals to create water-permeable bedding mortar with exceptional structural properties. Unlike conventional mortars, this material can be screeded and have pavers installed in a single operation due to its superior non-sag characteristics. An additional benefit is its ability to reduce efflorescence in natural stone and concrete, preserving the aesthetic appearance of your installation.

ROMEX – TRASS ADDITIVE provides the aggregate component, consisting of crushed ⅜” material comparable to ASTM No. 8 stone. Packaged in convenient 55-pound bags, this specially graded aggregate ensures consistent performance and proper drainage characteristics throughout the system.

ROMEX – ADHESION ELUTRIANT functions as a polymer-enhanced paver bonding agent that surpasses conventional thin-set mortars in performance. Applied to the underside of stone pavers, it creates superior adhesion to the TRASS BED while incorporating trass cement that provides dampproofing properties. This dual function enhances both structural integrity and moisture management.

ROMPOX PURE – PATIO, PERMEABLE JOINTING MORTAR completes the system, creating fully water-permeable joints that maintain structural unity. Comprised of ROMPOX – PURE resin and colored FILLER SAND, this material installs in a fluid state and cures to a hard finish that secures the entire paving surface as a unified assembly.

Installation Process: Step-by-Step Excellence

1. Surface Preparation

This system’s versatility allows installation over existing concrete slabs or directly onto properly prepared open-graded aggregate bases. For our demonstration, we’re working with an existing concrete slab installed with a 3% slope for natural water drainage. One of the system’s advantages is that properly sloped existing slabs require no special preparation before pavers installation. Installing pavers over concrete using this permeable system provides excellent drainage while maintaining structural integrity.

2. Preparing the TRASS Bed

Using a mortar mixer, combine one 55-pound bag of ROMPOX – TRASS BED COMPOUND with four bags of TRASS BEDDING AGGREGATE, maintaining a precise 1:4 ratio. Gradually add 2.9 gallons of water, continuing to mix until the material becomes slightly shiny and can be formed into a firm ball when squeezed. For smaller quantities, hand mixing using a mortar tub and paddle mixer attached to a drill provides adequate results.

The proper consistency is critical for system performance. The mixture should hold together when formed but remain workable for screeding operations. Add small amounts of water as needed to achieve the correct consistency, but avoid over-wetting which can compromise strength and permeability.

3. Bedding Layer Installation

Position 1½-inch diameter pipes on the slab as screed guides, checking that they’re level relative to each other and maintain the proper slope for drainage. Distribute the mixed TRASS material loosely across the surface, then screed evenly using the pipes as guides.

Once the surface is level, carefully remove the screed pipes and fill the resulting voids with additional mix. Trowel these areas smooth to ensure they’re flush with the surrounding bedding layer. This creates a uniform surface ready for paver installation.

4. Paver Bonding Preparation

In a 5-gallon bucket, mix the ROMPOX ADHESION ELUTRIANT using a paddle mixer attached to a drill. Combine half of a 55-pound bag with 1 gallon of water, mixing until achieving a plastic consistency that spreads easily without being too fluid.

Clean the back of each paver thoroughly to ensure optimal adhesion. Using a notched trowel, apply the Elutriant in a uniform layer ⅛ to ¼ inch thick across the paver’s back surface. The notched trowel creates consistent ridges that provide both adequate coverage and proper thickness control.

5. Paver Installation

Place each paver firmly into position on the prepared TRASS bed, tamping as necessary to achieve proper alignment with adjacent pavers. Take care to prevent the adhesion agent from squeezing into joint spaces, as this would compromise the system’s permeability characteristics.

Work systematically across the installation area, maintaining consistent joint spacing and checking alignment frequently. The system’s working time allows for adjustments during installation, but avoid excessive manipulation once pavers are set.

6. Curing and Sealing

Allow the installation to cure for 24 hours before proceeding with sealing operations. This curing period ensures the TRASS bed develops sufficient strength to support foot traffic and subsequent work.

Apply a premium-quality impregnating sealer rated for exterior use to protect the limestone pavers. Follow manufacturer recommendations for application and curing times. Proper sealing enhances the stone’s durability while maintaining its natural appearance and the system’s permeability characteristics.

7. Joint Completion

Once the TRASS bed compound has fully cured, begin the jointing mortar application. Clean joints to a minimum depth of 1¼ inches to ensure adequate jointing material thickness for proper performance.

Select the filler sand color that best complements your paver choice—in this demonstration, we used Neutral to blend seamlessly with the Indiana Limestone. Pour one 55-pound bag of filler sand into a mixing bucket and add the entire contents of one ROMPOX – PURE container, scraping thoroughly to include all material.

Mix continuously for 5 minutes until completely blended. The mixture will feel partially dry, but resist the temptation to add water, as this would compromise the curing chemistry and final performance.

8. Final Joint Installation

Pre-wet the paver surface with sufficient water to dampen thoroughly without creating puddles. This preparation helps the jointing material flow properly into the joints while preventing premature curing on the surface.

Pour the prepared jointing sand onto the surface and work it into joints using a rubber squeegee, ensuring complete filling. Maintain clean tools throughout this process by periodically spraying with water to prevent contamination of the binding agent and avoid leaving footprints on the surface.

After filling all joints completely, sweep the stone surface diagonally to the joint direction using a stiff nylon broom. This technique removes excess material without disturbing the joint filling. Complete the cleaning process with a soft-bristled broom for final surface preparation, removing any residual mortar that could affect appearance or permeability.

Advantages of Permeable Bonded Systems

Environmental Benefits

Permeable paving stones address growing environmental concerns about stormwater management. By allowing natural water infiltration, these installations reduce runoff that can overwhelm municipal storm systems and carry pollutants into waterways. The permeable characteristics help recharge groundwater supplies while reducing the heat island effect common with impermeable surfaces.

Structural Performance

Despite their permeability, these systems provide exceptional structural integrity suitable for various loading conditions, including vehicular traffic when properly designed. The elimination of frost heave from trapped water represents a significant advantage in cold climates, where traditional installations often fail due to freeze-thaw cycles.

Long-Term Durability

The polymer-modified materials resist degradation from weather, chemicals, and normal wear. Unlike conventional mortared joints that crack and allow water penetration leading to structural problems, permeable systems manage water as designed while maintaining structural integrity.

Reduced Liability

Property owners increasingly face liability concerns related to stormwater runoff. Permeable installations demonstrate environmental responsibility while potentially reducing drainage-related problems that could affect neighboring properties.

Design Considerations

When planning permeable bonded installations, consider the relationship between permeability and structural requirements. While the system handles normal pedestrian and light vehicular loads, heavy-duty applications may require modified approaches or additional structural support.

Evaluate existing drainage patterns and soil conditions to ensure the system’s permeability characteristics work effectively with site conditions. Areas with clay soils or high water tables may require additional drainage provisions to prevent water accumulation.

Installation Over Existing Concrete

One of the most significant advantages of this system is its ability to accommodate pavers on concrete slabs. This capability eliminates the need for expensive concrete removal while creating a permeable surface that addresses modern environmental requirements. The system’s ability to work over existing concrete makes it an ideal solution for retrofitting impermeable surfaces with environmentally friendly alternatives.

Maintenance and Long-Term Performance

Pervious pavers installed using this bonded system require minimal maintenance when properly installed. Periodic cleaning of joint surfaces may be necessary in areas with heavy organic debris or fine soil infiltration. However, the robust nature of the polymer-modified jointing material resists most common maintenance issues.

Unlike loose-set permeable systems that may require joint material replacement, bonded systems maintain their integrity through years of service. The structural nature of the installation prevents settling and movement that plague other permeable options.

Investment in the Future

Permeable bonded paving systems represent more than just another installation method—they embody a comprehensive approach to sustainable construction that addresses environmental concerns without compromising performance. The initial investment in premium materials and proper installation techniques provides returns through reduced maintenance, enhanced durability, and environmental compliance.

As environmental regulations become increasingly stringent and property owners seek sustainable solutions, permeable bonded systems offer forward-thinking approaches that anticipate future requirements while delivering immediate benefits.

Professional Installation Success

Successfully installing permeable bonded systems requires understanding both the materials and the methodology. The precision required in mixing, timing, and application makes these systems ideal for contractors committed to quality and innovation. The comprehensive nature of the ROMEX system provides all necessary components designed to work together seamlessly.

Ready to embrace the future of sustainable hardscaping? Permeable bonded systems using Polycor’s Indiana Limestone offer the perfect combination of environmental responsibility and structural performance. Contact a Polycor expert today to explore how these innovative installation methods can enhance your next project while contributing to environmental sustainability goals.

The future of paving technology is here, offering solutions that benefit both property owners and the environment. By adopting advanced permeable bonded systems, you’re investing in long-term durability, reduced maintenance, and the strongest return on investment while demonstrating commitment to sustainable construction practices.

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