Testing procedure to evaluate a stone panel’s tendency to warp or bow

Certain solid marble slabs will permanently warp in response to uneven heating and cooling and a moisture variation in the stone. Using StonePly for your cladding project eliminates this problem. Various StonePly granite, marble, and travertine panels have been tested using the European procedure for testing for stone slab bowing. In the test, the slab is partially submerged in water. The unsubmerged face of the slab is exposed to radiant heat. The slab is subjected to repeated cycles of heating and cooling.

In testing, 40 cycles are considered sufficient to show if a marble slab has a tendency to bow. StonePly natural stone panels were subjected to five times that number of cycles. After 200 cycles, StonePly natural stone panels showed no discernible bowing or warping.

The Challenge and The Solution

The ability of StonePly to stay flat has led to its use in several projects. The historic Arkansas Power and Light Building was built in the 1950s. Over time, the cladding stone began to warp and bow. Entergy Corporation, the owner of the building, made the decision to replace the original stone. After extensive research and assistance from Cromwell Architects and Engineers, Entergy selected StonePly. StonePly stone panels that matched the original stone were used. The StonePly panels gave Entergy the ability to keep the original stone finish and style while simplifying replacement and reducing the weight on the historic structure. The rigid aluminum honeycomb composite backing keeps StonePly stone panels straight and stable.

StonePly Panels: Extensively Tested and Proven

To ensure that there would be no problems with the new cladding, the StonePly panels were rigorously tested by WJE (Wiss, Janney, Elstner Associates) of Chicago. The panels were subjected to testing for freeze-thaw resistance, resistance to acid rain damage, bond strength, flexural strength, and other properties. StonePly panels performed extremely well. In a review of the natural stone panel testing results, Michael Stenstrom of SSI Engineering stated “SSI is very comfortable with stating that these panels exceed any building code requirements for bond strength, tensile strength, flexural strength, or horizontal shear strength.”

For More StonePly Information

If you are interested in lightweight stone panels that can resist bowing and have superior strength and durability, visit the StonePly website to learn more about our innovative product. Here you’ll find resources telling you about the backing options for our versatile panels and the vast number of granite, limestone, onyx, marble, and travertine varieties we have available. Whether you are interested in natural stone wall cladding, illuminated natural stone partitions, or another interior or exterior element, we can help you decide whether we are the right supplier for you during a free initial consultation. We’ll also give you a no-charge personalized estimate based on the requirements of your project. Call us at 903-454-4630 or fill out the contact form on our site to get started.

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Stone panel bowing

When natural stone panels are used as cladding for retail stores, high-rise apartments, hotels, and other structures, both contractors and building owners hope that the stone will remain perfectly flat over time.

Unfortunately, this isn’t always the case. When stone panels are installed outside and exposed to the elements, bowing may occur. In stone panel bowing, the stone facade is permanently damaged and takes on a concave or convex appearance. In addition to being an unsightly problem, bowing reduces flexural strength and increases the chances of stone failure. This can lead to costly repairs down the road and increase the risk of injury. The good news is that choosing the right stone panels can completely eliminate this costly and potentially dangerous issue.

Thermal Hysteresis and Stone Panel Bowing

One of the major causes of bowing is thermal hysteresis. This is particularly a problem with thin-veneer marble, in large part because of the coarse veins it often contains and its uneven strength.

The outside-facing surface of the stone panel expands and contracts as it is exposed to warmer and then cooler temperatures. In some cases the panel does not contract fully, which can lead to bowing. A greater load is placed on the stone anchors as a result, which exacerbates the problem and further increases the risk of failure.

Preventing Bowing of Natural Stone Panels

How can I ensure bowing will not be an issue with my natural stone panels? This is an essential question if you have been asked to supply exterior marble cladding. Luckily, the answer is simple: Use natural stone panels crafted by StonePly. Consider the following:

• The entire surface of our marble panels is attached to an aluminum honeycomb backing using aviation epoxy. This eliminates weak spots and gives the marble cladding superior rigidity and flexural strength.
• Various granite, marble, and travertine panels by StonePly have been subjected to testing designed to determine whether a panel is likely to bow. In this accepted test, 40 heating and cooling cycles are considered sufficient to show a stone does not have a tendency to bow. StonePly panels were subjected to 200 cycles and showed no noticeable bowing or warping.

For More StonePly Information

The ability of StonePly natural stone panels to resist bowing is just one property that makes them preferable to heavy slab stone for many applications. To learn more about the many advantages of our natural stone panels and our track record of success, visit the StonePly website.

If you think our natural granite, marble, limestone, or travertine panels might be the right choice for your project, feel free to get in touch with us any time to request a free initial consultation and a personalized estimate. You can call us at 903-454-4630 or complete the brief form on our contact page.

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