Category: Rusted Rod Cracks

Rusted Rod Cracks in Countertops Repair

Many homeowners are surprised to find a sudden crack appearing along the narrow strip of stone in front of their kitchen sink. This common issue is rarely a fault of the stone itself, but rather a result of a hidden structural component: the internal metal reinforcement rod. These rods are designed to provide structural reinforcement during the handling process, they can eventually become the primary cause of stone failure if they begin to rust. This oxidation leads to expansion, which creates enough internal pressure to crack the granite from the inside out.

Why is there a rod in my granite?
“Rodding” is a standard industry practice used to strengthen granite or marble during the most vulnerable stages of its life: transportation and installation. Because the area around a sink cutout is thin and fragile, fabricators cut a groove into the underside of the stone and embed a rod to prevent it from snapping while being moved or set into place.

Once the countertop is securely installed on your cabinets, these rods serve virtually no purpose for daily use. The cabinets provide the necessary structural support, leaving the rod dormant inside the stone.

The Science of the “Rust Burst”.
The problem begins when water penetrates the stone or the seams around the sink. If a standard carbon steel rod was used, moisture causes the metal to oxidize and rust. As iron turns to rust, it expands significantly, exerting tremendous internal pressure on the granite. Since granite is a rigid material with no room to “give”, the expanding metal eventually forces the stone to split, resulting in the characteristic crack seen in the “before” images.

Prevention and Better Alternatives.
To avoid the costly “Full Repair” process, which involves detaching broken pieces and physically removing the oxidized metal, the preventative measures are essential.

Proper Caulking: The most critical defense is maintaining a perfect seal. Re-caulking around the sink with clear silicone is vital to stop water from reaching the internal rod.

Material Selection: Modern standards suggest moving away from carbon steel.

– Fiberglass Rods: These provide the necessary tension during transport, but are completely immune to rust.
– Stainless Steel: Though more expensive, stainless steel rods offer high strength without the risk of corrosion induced expansion.

Professional Restoration.
If your countertop has already cracked due to a rusting rod, a simple surface patch in most cases won’t suffice. A permanent fix requires detaching the broken piece and removing the rusted metal rod to stop the expansion at its source. Once the rod is removed, the stone can be reset with specialized colored epoxy and re-polished to restore its finish.