Part Two: Ensuring Natural Stone Pavers Are Installed To Last

Part Two: Ensuring Natural Stone Pavers Are Installed To Last

Proper Maintenance Of Natural Stone Starts With Intentional Design

Natural stone pavers maximize a project owner’s investment due to their beauty, durability and longevity. They are a popular hardscaping choice because they can withstand the elements in various environments. Natural stone is the original building material of the Egyptian and Greek monuments that are still standing today.

Natural stone is cost-effective when it comes to maintenance. It is also environmentally friendly because the sourcing process has less impact than manufacturing, and natural stone can be reused. There is also versatility in the aesthetics. Stone can be rustic (riven surface) or contemporary (honed) and can be used in endless shapes and designs.

We started discussing how to properly install paving in the July/August 2022 issue on pages 39-41. Installation is one step in ensuring that pavers will last to their full potential, but proper maintenance will help keep them functional and beautiful for the long haul. The secret to ensuring the longevity of pavers is remembering that maintenance considerations start with the initial design and intent of the space.

Mother Nature’s Influence

Handing over hardscaping maintenance may seem straightforward, but it gets more complicated when natural stone sees a variance in weather. A stone that might be appropriate in south Texas or southern California for a paving application is not necessarily a material that would be appropriate in Chicago or St. Louis, where there is a high number of freeze-thaw cycles. The climate factor is important, as selecting the right materials with the appropriate physical properties to withstand the elements will be critical.

Microclimates, where a small area differs from the surrounding climate, are also an important consideration. Microclimates are defined by the moisture, temperature and winds of the atmosphere near the ground, vegetation and soil, in addition to the latitude, elevation and season.

The Science Behind Stone

When a stone’s physical properties take a backseat to design and aesthetics, proper maintenance can be an impossible goal, affecting the project’s overall quality. Knowing the physical properties before selecting a stone will help ensure your structure looks as impressive in the coming decades as it does on day one.

Each type of stone has specifications that may or may not work with the application. For instance, limestone, marble, granite and travertine pavers perform well in low-traffic and warm climates that do not experience freezes and thaws, so longterm maintenance is minimal. It also matters if the paving regularly has water on it and the region you are in—or how easily the stone is worn or smoothed by foot traffic.

Using those same materials in an environment with harsh weather makes them susceptible to decomposition if exposed to ice salt acids. Silica-based materials are less absorbent and will withstand those conditions with minimal impact.

One key to understanding natural stone’s physical properties is working with a natural stone supplier who can provide guidance early in the design process. A design team may have a specific aesthetic goal in mind, but you should consider if the choices will perform in the environment. Understanding each stone’s properties will ensure the right stone has been selected for the project and bolster the architect’s case for their choice of stone.

National Marine Museum in Quantico, Virginia

National Marine Museum in Quantico, Virginia

The American Society for Testing and Materials International (ASTM) created two testing methods to determine a stone’s physical properties by absorption rate and abrasion resistance to help decide if the material will work in the environment. ASTM develops standards for materials to provide a consistent and realistic set of testing procedures for stone products and is recommended as a first step in deciding on a stone type.

Proper Installation

Even with the right stone, if it has not been correctly installed, there will be issues. However, sometimes the issue comes up as a maintenance problem, even though it was probably due to a shortcut during installation.

Consult with experienced stone setters for specific nuances, such as proper air gaps in vertical installations like retaining walls. Air gaps can eliminate the effect of water moving through the soil and leaving behind salts on the natural stone.

In exterior locations, natural stone does not need a sealer. Sealers cannot allow a material used in the wrong location to survive—it is more appropriate for other types of paving. Our best advice is to leave the stone natural and not apply a sealer, as this can compound other issues. If a sealer is used, it can wear off over time, leaving the stone full of spots.

Maintenance

Natural stone pavers are easy to maintain if the right materials are used—and the installation is done correctly. General maintenance can be scheduled once a year. This is an excellent time to check for cracks or broken seals that can prevent damage from dirt and othe environmental elements.

Water is the ideal way to clean and remove debris and restore materials. A light pressure washing annually goes a long way in maintaining your surface. Pay special attention to joints that can be impacted over time. Building elements, like joint compounds, will need to be recaulked every four to eight years because they naturally shrink away, and the gaps allow water in. Mortar, on the other hand, lasts longer unless it is used in an area with a colder climate.

The design, material selection and installation process should start with the end in mind. Maintenance may be the last step in preserving a hardscaping project, but it should not be the last thing to consider.

Get In Touch With...

Bryce Kock

Phone: (830) 730–6765

Email: bkock@coldspringusa.com

www.coldspringusa.com