The Expert’s Guide to Countertop Bracket Design
While sleek and beautiful, solid steel brackets are designed to hold the weight required in a countertop application including granite, wood, and marble. Here are the standards in countertop support bracket designs from experts in the National Kitchen & Bath Association (NKBA).
First, let’s get familiarized with the anatomy of a countertop support bracket:
Recommended Countertop Design Standards
Countertop Support Material:
What is the best material for a countertop support bracket? A36 steel.
If a weaker material is used, it is recommended that concessions be made in terms of the size or number of supports to account for the weaker material.
Countertop Support Thickness:
All weight-bearing countertop support brackets should be made to a minimum thickness of 7 gauge (.18”) in the gusseted configuration and 1/4" thickness in the non-gusseted configuration.
Countertop Support Width:
Countertop brackets actively supporting a countertop can vary significantly in design and specifications. However, it is recommended that the supporting flange directly under the countertop surface be at least 1.5” wide.
Countertop Support Flange Length:
How long should my countertop support flange be?
It is best to use a countertop support bracket that has a top flange length (flange directly under the countertop surface) that extends within 4 inches to the end of your counter.
We also recommend that the top flange does NOT extend past twice the length of the down flange (flange extending down the support structure in a standard countertop bracket configuration). The exception is an instance where additional support is being added along the top flange length — such as an application using cabinet strap brackets.
Countertop Support Holes:
Holes cuts or drilled into the countertop support bracket may or may not be countersunk. Regardless of treatment holes, the diameter of the hole placed in a countertop support bracket should be determined in such a manner to provide for an adequate-sized fastener to be able to be used for fixing the countertop support to the support structure.
Holes in countertop brackets should NOT exceed 2/3 (two-thirds) of the flange’s width in which they are placed. Holes should NOT be drilled in a position on the flange where they interfere with the outer edge of the support bracket or cause the flange material to weaken and tear away from the fastener.
Distances between holes on down flanges of countertop brackets attached to the support structures should NOT exceed 12 inches (1 foot). A minimum of two holes is recommended in any supporting flange of a countertop bracket attached to the support structure.
Holes may or may not be placed in the top flange based on application.
Ready to get started? Explore our wide variety of metal countertop support brackets:
