Overhang Supports: How Much Cantilever is Safe?

Cantilever: a projecting beam or member supported at only one end: such as a bracket-shaped member supporting a balcony or a cornice. – Merriam Webster

Staying true to the modern minimalist design aesthetic that is so popular these days, overhanging countertops, and floating shelves and mantels seem to be taking over the residential market. When installing your own overhanging countertops or floating shelves, it’s important to know how to do things properly. Follow these tips and you can design and your own kitchen or den with a modern look that will increase property value, boost your entertaining confidence among friends, and even minimize upkeep!

Cantilever Installation Tips:

• What material is your shelf or countertop?
• If you are installing overhanging countertops, how thick is your material?
• What is the total overhang distance?

Equipment

Right On Brackets are manufactured using premium American steel giving them a robust load bearing capacity. Whether you’re installing a decorative shelf or a granite countertop, you’ll want to be sure you’re mounting a bracket that will handle not only the combined weight of the material and whatever the shelf is holding, but also consider where the weight will be distributed when in use.

Materials

The thickness of your material is very important to consider. While a thicker slab will add more weight, it will also provide more internal structural support. The real question that you’ll want to ask yourself when considering the proper hardware is the density of your material. By understanding the characteristics of the different stones and hardwoods, you can make a more informed decision while purchasing support brackets. For all countertops, we recommend either ⅜” or ½” bracket thicknesses. If your material is thick or the overhang is over 12”, we recommend a ½” thick bracket for extra strength. 

Stone Countertops

Industry professionals classify granite and quartz as hard stone. Hard stones have a greater potential to support themselves over a slightly larger cantilever. Marble on the other hand is softer by comparison requiring more support and should be cantilevered slightly less.

Wood Shelving

We can also make a similar assumption when it comes to wood. Cherry and maple are a popular choice for shelving due to their lightweight and rigid qualities. These woods will not require the same level of support as an OSB shelf. In fact most forms of particle board will serve the opposite function. These materials will require a more rigid support throughout the overhang.

Best Practices

There are a few industry standards that are often considered when installing any sort of overhang. Keeping these qualities in mind, a carpenter might tell you that you’ll get away with cantilevering ⅓ of the total overhang. A stonemason might scoff and insist that you wouldn’t even consider cantilevering anymore than 4 inches. 

DIY

So, onto the question at hand. How much of a cantilever is safe? Considering these factors, we wouldn’t always recommend the industry standards. The truth is that it really depends on your project. Your decorative hardwood shelves will provide more wiggle room as the wood will have more flex, but also be much lighter than stone. By viewing the industry standards through the lens of being helpful guidelines, you make a more informed decision on what size and type of brackets will be best for your project.