A customer recently asked us to install an 8 foot long granite bartop that was 18 inches wide on a 4 ½ inch wide pony wall separating the kitchen and dining room. He wanted a 2 inch countertop overhang on the kitchen side of wall which left nearly 12 inches of granite overhanging the dining side of the wall.
He was surprised when we told him he’d have to install a number of 6″ corbels to support the bar top. He assumed all the installers had to do was “glue” the bartop to the top of the wall. While the pony wall itself could easily bear the weight of the bartop, without corbels it would turn into a fulcrum. Imagine a 200 lb. man sitting on one end of a teeter-totter and a 40 lb. child on the other end and you can to guess the outcome.
It is a standard installation rule that 70% of the total countertop width of a countertop must be supported by base cabinets, knee walls, corbels, etc. Different countertop materials have different requirements. As the chart indicated Solid Surface countertops may only overhang 6 inches without additional support.
3 cm Quartz (engineered stone) can handle a 14 inch countertop overhang without additional support, 3 cm Granite overhangs should not exceed a 10 inch overhang without additional support, bearing in mind the 70% rule. The supports may be corbels, flat steel (3/8” by 3”) or a design incorporating an apron and table legs. If you have questions about what kind of support should be used feel free to contact Solid Surface Designs at (417)258-2787 or keith@ssdionline.com.
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