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Long Term & Low Maintenance Paving Solutions

Permeable paving refers to a hardscape surface that allows water to infiltrate and drain through the surface into the underlying sub-base and native ground, rather than being directed to stormwater drainage systems. This helps mitigate stormwater runoff issues, such as flooding and water pollution as well as promoting healthy ecosystems by returning water back to the water table and recharging the earth’s aquifers.

ROMEX offers multiple solutions for creating resilient and permeable hardscapes. We provide resin-based jointing mortars, paver base bedding mortars and gravel-binding products that all provide water-permeable properties for bound and unbound paving assemblies.

The benefits of using ROMEX permeable paving solutions include improved stormwater management, reduced flooding and water pollution, increased durability and strength, reduced maintenance costs, and an overall more sustainable and eco-friendly approach to paving. Additionally, our solutions are designed to be load-bearing, frost-resistant, and highly water-permeable, making them suitable for a wide range of residential and commercial applications. Click here to view our 5 and 10-year warranty system and view all the benefits ROMEX products have to offer.

Romex provides multiple solutions for creating resilient, permeable hardscapes. Primarily, Romex resin-based jointing mortars provide a water-permeable grout for jointing unit pavers of almost any kind, for both unbound (‘sand-set’) and bound (‘mortar-set’) paving assemblies. Unit pavers that are specifically designated as “permeable pavers” –  with larger joint spaces in between – can benefit in particular from Romex jointing solutions (see section below).

Secondly, for bound assemblies, Romex Trass Bed drainage bedding mortar works as an industry-first ‘permeable slab’. The incredible strength of the polymer-enhanced binding agent, with proprietary Trass additive, uses aggregate for it’s structure – no rebar required – providing superior load-bearing properties, inhibits efflorescence, and yet provides small but sufficient porous channels through which rainwater can travel.

Thirdly, applying the same resin technology, Romex provides hyper-resilient resin-bound and resin-bonded gravel solutions for tree surrounds, pathways, garden edging and the like. For resin-bound gravel, permeability is essentially the same as if the gravel was installed on its own.

For jointing mortars, let’s look at how Romex’s revolutionary jointing mortar technology makes permeability possible.



ROMEX TRASS BED drainage bedding mortar is a ‘permeable slab’ for a bound assembly (‘wet-lay’ or ‘mortar-set’) of unit pavers. TRASS BED replaces a conventional, rebar-reinforced slab; this layer in the assembly is no longer required. In many cases, neither is the drain mat layer. TRASS BED is the slab and the drain mat – all in one. As such, ROMEX TRASS BED is the intended and ideal sub-grade compliment to ROMEX Permeable Jointing Mortars, for any bound paving assembly.

Used in conjunction with the ROMEX ADHESION ELUTRIANT thin set bonding compound, these three elements – bedding, bonding and jointing – form the ROMEX “RSG” System, which provides a unit paver hardscape that is load-bearing, frost-resistant and highly water-permeable – the first and only one of its kind in the industry.

Superior strength, resilience and permeability are achieved with only a fraction of the thickness compared to conventional – roughly 40mm or 1½” deep for pedestrian loads and 75mm or 3” for vehicular (call us to discuss your specific site conditions). Forming is no longer required, nor is rebar. Instead, TRASS BED uses 4-8mm aggregate for its structure, which provides a more workable consistency that holds shape during install and won’t slough during paver laying. After curing, the bonded aggregate pieces provide integrity – while still leaving tiny channels between each piece of stone through which water can travel.

ROMEX TRASS BED is suitable for installs on architectural slab with waterproof membrane, with or without insulation, or be installed directly onto clear crush or similar for installs on grade.

As a final note, this means ROMEX TRASS BED is also frost-resistant – because water is never ‘trapped between a rock and a hard place’. If cracks form in conventional paving, liquid water will get in where it isn’t wanted, and when it freezes and expands, the forces of nature will eventually win over the bonding strength of the assembly, heaving and pushing pavers out of surface alignment. With ROMEX TRASS BED, this risk is eliminated, because water can pass straight through, evaporate out or, if suddenly frozen while in the bedding itself, it can expand and contract within the matrix, over and over again. With a Romex RSG paving assembly, ‘freeze / thaw’ has become a thing of the past.

Call us to learn more about how you can ensure your next bound assembly will stand the test of time by letting water do what it needs to do – without affecting your paving surface.


There are numerous permeable paver options on the market, with offers from most major manufacturers. ‘Permeable pavers’ are not themselves pervious, but instead have wider joint spacing between each paver to allow stormwater to flow down and through to the sub grade below. Pre-cast permeable pavers have larger built-in joint spacers, and natural stone pavers are simply set with a wider joint line, commonly from 6mm wide and up.

However, all permeable pavers have a common design component for their assembly – that the joints are filled with ‘loose grit’. This creates an inherent challenge for the performance, resilience, and cost of the system.

‘Loose grit’ does not stay in place over the long term to keep pavers held together. ‘Loose grit’ does not stop weeds from growing up and ants from digging down. ‘Loose grit’ will collect organic matter and grow moss which inhibits permeability. ‘Loose grit’ will collect other things, like garbage and cigarette butts. And finally, when it gets dirty or mossy, ‘loose grit’ cannot be cleaned or pressure washed.

<i>When loose grit goes missing, surface integrity is compromised. </i>

When loose grit goes missing, surface integrity is compromised.

<i>When debris collects, loose grit cannot be pressure washed. </i>

When debris collects, loose grit cannot be pressure washed.

The remedy presented for cleaning the joints and restoring permeability? Vacuum out the compromised loose grit from the joints with a large vacuum truck, and re-install new loose grit – and start the cycle over again.

This is commonly required to be re-done each year. So while these jointing materials are economical up front, re-installation and/or repair costs can continue to add up over time.

We ask – can’t there be a better way to build lasting, functional, economical, and low-maintenance permeable paving?

There is.


With Romex resin-bound permeable Jointing Mortar, it’s a one-and-done solution. Installed in a fluid state, the resin-aggregate mixture fills every joint completely and without voids, sinking down deep in between each paver, connecting to their sidewalls and to the bedding layer beneath. After it sets, the unique structure of Romex Jointing Mortar creates an obscenely strong and comprehensive connective network between all the pavers, securing them together as one to form a strong, cohesive surface – while still allowing rainwater to flow down and through the paving assembly.

<i>With Romex, every joint is filled completely. </i>

With Romex, every joint is filled completely.

<i>Permeable pavers finished perfectly with Rompox Drain. </i>

Permeable pavers finished perfectly with Rompox Drain.

Romex Jointing Mortar will stay in place and keep the pavers secure. Romex Jointing Mortar will stop weeds from growing and stop ants from digging. Romex Jointing Mortar will limit the collection of garbage or debris. And when the surface gets dirty or mossy? It can be cleaned and pressure washed, as often as the site requires, and the paving surface aesthetics – and permeability – can be restored.

So when you want resilient and permeable paving system that lasts the test of time: don’t mess about. Do it right. With Romex.

For more on permeable paving, check Wikipedia here.


Need some clarification? Contact our experienced and friendly team to learn more about our products and services.



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