I would not be comfortable with corbels supporting granite marble or any other stone top that extends past 2 3 to sit on.
Tensile strength granite countertop.
Photo courtesy of concrete countertop institute some countertop contractors use other reinforcement materials such as expanded metal and report good results.
The information below gives homeowners an brief overview of the strength attributes of two popular stone types and their respective mohs hardness ratings.
Elastic young s tensile modulus.
Ultimate uts 39 mpa 5 7 x 10 3 psi.
Granite if you are wary of scratching or cracking your stone counter tops you may consider installing granite.
24 mpa 3 5 x 10 3 psi.
But use of carbon fiber has migrated to concrete countertops because it has high tensile strength and is thin enough to fit in tight spots.
70 gpa 10 x 10 6 psi.
The bottom line is that your granite top could crack and tumble to the kitchen floor with as little as 100 or 150 pounds that s loaded at the center of the 50 inch span.
While i can t say exactly what the tensile strength of your granite top is for its current thickness it s usually only ten percent of what it exhibits in compression.
27 gpa 3 9 x 10 6 psi.
Dielectric strength breakdown potential 8 5 kv mm 0 33 v mil.
You must realize that most if not all stones used for countertops have little to no tensile strength.