In the construction of artificial rockwork, many companies employ a method that involves shaping the rocks with rebar, overlaying the framework with lath, and then pumping concrete over the assembly. Once the concrete sets, a finish texture coat is applied to achieve the desired aesthetic. While this approach may seem effective at first glance, it presents significant structural concerns that compromise the long-term integrity of the rockwork.
The primary issue with this method is that the rebar framework remains exposed inside the structure, inadequately encased by the concrete. This exposure allows air and moisture to come into contact with the rebar, initiating the oxidation and corrosion process almost immediately. While the dry climate in Arizona can delay visible signs of deterioration, the structural degradation begins on day one. Over time, the corrosion weakens the rebar, causing the concrete to crack, spall, or shift, ultimately leading to structural failure.
In many cases, the initial signs of failure become evident well beyond the standard two-year warranty period offered by most contractors. In Arizona, where the dry environment masks early warning signs, structures constructed using this method may begin to fail as soon as four years after installation. At this stage, the damage is often extensive, requiring significant and costly repairs to restore the structure’s integrity. I have personally observed instances where artificial rock features, built using this technique, have suffered massive failure within just a few years, highlighting the inherent flaws in this construction approach.
To ensure the longevity and reliability of artificial rock structures, it is essential to adopt construction methods that fully encase the rebar in concrete or gunite, preventing exposure to the elements. This proactive approach eliminates the risk of oxidation and significantly extends the lifespan of the structure. Homeowners and contractors alike should prioritize durability and quality over short-term cost savings to avoid future expenses and potential safety concerns.