This construction practice made me curious. As soon as I lifted the 3/16 inch thick by 2 inch wide steel bars (now routed into the plywood subtop under our granite counter overhang) I noticed that these 12 foot long metal pieces bend considerably under their own weight.
It is common practice to place these under the granite, spaced about 1 foot apart perpendicular to the length of the overhang, to reduce or eliminate the need for corbels (those wood support pieces you hit your knees on at a bar).
Even a 4 foot section of steel bar will bend a little bit. I don't understand how this makes a significant difference in preventing the granite from cracking when someone decides to jump up and down on the countertop.. since the steel bends.
Is this because the steel bends more uniformly across the entire span, whereas plywood can bend at sharp points wherever the plywood has a weak spot? Is it because these steel bars routed into the plywood subtop and glued with epoxy help more with tension and compression, rather than just resisting bending?
It is common practice to place these under the granite, spaced about 1 foot apart perpendicular to the length of the overhang, to reduce or eliminate the need for corbels (those wood support pieces you hit your knees on at a bar).
Even a 4 foot section of steel bar will bend a little bit. I don't understand how this makes a significant difference in preventing the granite from cracking when someone decides to jump up and down on the countertop.. since the steel bends.
Is this because the steel bends more uniformly across the entire span, whereas plywood can bend at sharp points wherever the plywood has a weak spot? Is it because these steel bars routed into the plywood subtop and glued with epoxy help more with tension and compression, rather than just resisting bending?
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