Decomposed Granite Stabilizer – Why Is It Important?

Decomposed granite is an increasingly popular hardscaping option being used in both large and small projects across the country. Although this material has some inherent drawbacks, these have been largely addressed by the use of stabilizers such as Organic-Lock™. If you’re here to learn more about this particular product click here to read about how it works or see the types of projects it has been used for, or read on for more information on decomposed granite and how it can be utilized.

In the past, using loose aggregates like decomposed granite required a hard choice between durability and utility. Surfaces laid with decomposed granite have a more natural look and allow natural filtration, but without a gravel binder they can suffer from erosion and washouts [1].

When high-quality stabilizers specifically designed to be used with loose aggregates like decomposed granite came to market these issues were minimized. These products work to prevent the problems of durability inherent with this material.

While rain weakens the integrity of unstabilized decomposed granite surfaces, binders like Organic-Lock™ removes this limitation. The natural compounds in the stabilizer expand when wet, holding the aggregate in place.This reduces the erosion rate while still allowing natural filtration to occur. Under laboratory conditions, aggregate blended with Organic-Lock™ only lost a total of 3% of its material after 120 minutes in a rainfall simulator compared to close to 100% when unstabilized.

With an increasing focus on more natural and environmentally friendly hardscaping material, it is no wonder that using stabilized decomposed granite is being used for an increasing variety of hardscaping projects.

Uses For Stabilized Decomposed Granite

With the use of a stabilizing granite binder, the number of uses for decomposed granite has expanded.

In the past it would not have been advisable to use this material for some of the following applications, but with the added erosion resistance provided by a stabilizer, more and more hard surfaces can benefit from the natural look and feel of decomposed granite.

Paths and Driveways

In both domestic and commercial projects, stabilized decomposed granite is a great choice for paths and driveways. As explained by Gardenista, the feel of a natural surface underfoot is better than hard surfaces such as concrete or asphalt and blends better into lawns, gardens and other landscaping [2].

The durability of a stabilized aggregate also greatly reduces the need for costly ongoing maintenance. Erosion is greatly reduced by the use of a stabilizer such as Organic-Lock™ and if damage is done to the path or driveway, it can easily be fixed with simple hand tools.

Patios

The introduction of stabilizers has made the use of decomposed granite on larger outdoor squares, seating areas and patios much more effective.

These large hardscaped areas have traditionally been paved with concrete or asphalt which are impervious and require extensive drainage systems to manage runoff [3]. As a natural material, decomposed granite allows for natural infiltration of rainwater, which often negates the need for costly and complex stormwater drainage systems.

This represents a saving on the initial capital outlay and also has the potential to reduce the lifetime cost of a project due to reduced local government taxes for stormwater utilization [4].

Trails

Tracks and trails in nature reserves and national parks have long made use of loose aggregates. The natural look and feel of these surfaces along with their ease of installation made them perfect for this purpose even with the problems of erosion and ongoing maintenance that these surfaces experience.

The use of Organic-Lock™ as a stabilizer removes the issue of erosion and washouts from the equation. Any additional cost of using a stabilized aggregate on these paths is more than offset by the reduced repair and replacement schedule.

Benefits of Stabilized Decomposed Granite

Although some of the major benefits of stabilized decomposed granite have been briefly mentioned already, there are many others that are less obvious which will be outlined for you below.

Natural Look and Feel

The latest trends in hardscaping and landscape design call for a more natural look and feel [5]. Stabilized decomposed granite is the perfect way to achieve this without the need to sacrifice the stability and durability of more traditional paving solutions.

Affordable

Stabilized natural aggregates are typically much cheaper than concrete and even asphalt surfaces. The cost of a stabilized aggregate path can be comparable to the cost of other more permanent products like asphalt or concrete, but the savings found with working with a stabilized decomposed granite surface occurs after the installation itself.

Decomposed granite stabilized with a high-quality binder can have damage fixed with basic hand tools and a small amount of new material. This reduces lifetime maintenance costs significantly and ensures paths and walkways are always well maintained in adherence with disability access standards.

Improved Drainage

Impervious surfaces like concrete increase runoff velocity and can cause flooding during extended rainfall, while also preventing aquifers from naturally recharging [6]. Decomposed granite surfaces allow water to infiltrate naturally and this is not impeded by a binder like Organic-Lock™.

Governments across the country have begun to realize the problems caused by poor infiltration and are penalizing projects that have too much runoff while also incentivizing the use of natural paving materials due to their high infiltration rates [7].

These guidelines are great for the environment and will also help you keep the project budget in the black due to the reduced need for complex drainage systems.

Meet Environmental Standards

One of the most important benefits of decomposed granite surfaces is how they can help you meet environmental certifications, such as LEED which are the new standard for large projects.

Leadership in Energy and Environmental Design (LEED) is a set of standards set by the US Green Building Council (USGBC) to help measure and hopefully reduce the impact of new projects. Government credits and rebates are typically contingent on the LEED certification of a project [8].

The use of decomposed granite can help satisfy a range of standards relating to local material choice, storm water management and the heat island effects.

What Exactly is Decomposed Granite?

This material occurs naturally and is formed by the normal weathering of granite rock. Granite is a common variety of stone found all over the country and it will generally be possible to source decomposed granite from a local source. This can help keep transport costs down while also contributing to a higher LEED rating, as the standards prioritise the use of local, natural materials [9].

Depending on the type of granite and the level of weathering decomposed granite can be in larger pieces the size of pebbles or as small as sand particles. The colour of the material is natural and also varies depending on the type of granite found in the local area.

Being an all natural material, decomposed granite in conjunction with the all natural stabilizer is perfect for outdoors use. Unlike other aggregates, decomposed granite will not cause issues when spread onto lawns as it will break down over time and is not as hard as other types of stone [10].

As an all natural product that is easily available in many regions there is no better option for the hard surfaces on your next project.

Why Should You Use Decomposed Granite?

The benefits of stabilized decomposed granite are clear. Not only is it a natural product, with the use of a stabilizer, surfaces laid with this material can be durable enough to stand up to the demands of the heaviest foot traffic.

Organic-Lock™ prevents the issues of erosion and washouts that typically occur with loose aggregates like decomposed granite, without impacting the natural look and feel of the surface or impeding the natural rates of infiltration.

Probably the biggest benefit of this material is the cost effectiveness. The low cost of laying and maintaining decomposed granite surfaces along with the potential tax savings associated with LEED certification make this the perfect choice for both small and large scale projects that incorporate hard surfaces.

If you’re interested in using Organic-Lock™ on your next project, find your closest dealer here.

References

[1] Scholz, M., Grabowiecki, P. (2007). Review of permeable pavement systems. Building and Environment, 42(11), 3830-3836. https://doi.org/10.1016/j.buildenv.2006.11.016.

[2] [5] [10] Jenkins, E (2018). Hardscaping 101: Decomposed Granite. Gardenista. https://www.gardenista.com/posts/hardscaping-101-decomposed-granite/

[3] [7] Frazer L. (2005). Paving paradise: the peril of impervious surfaces. Environmental health perspectives, 113(7), pp. 456-62. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1257665/

[4] Terhell, S.L., Cai, K., Chiu, D., Murphy, J. (2015). Cost and Benefit Analysis of Permeable Pavements in Water Sustainability. ESM 121 Final Paper. Accessed: 24 Feb 2019. Available from: http://watermanagement.ucdavis.edu/files/5414/3891/2393/A03_Terhell_Cai_Chiu_Murphy_ESM121_FinalReport.pdf

[6] Perlman, H. (2016). Why is this house wearing stilts? USGS Water Science School. Accessed: 25 Feb 2019. Available from: https://water.usgs.gov/edu/impervious.html

[8] Ashley, E. (2008). Using Pervious Concrete to earn LEED points. Concrete in Focus. Accessed: 26 Feb 2019. Available from: https://www.nrmca.org/research/CIF%20Winter%2008%20Perv%20Conc%20LEED.pdf

[9] Abel, K. (2016). Trends in LEED Buildings and their Effects on Urban Permeability. GIS For Water Resources. Accessed: 24 Feb 2019. Available from: https://www.caee.utexas.edu/prof/maidment/giswr2016/Papers/Abel.pdf