That depends on many factors regarding the project material and the thickness of the surface.
Quartz countertop overhang without support.
Yes you can extend the overhang on a kitchen island countertop.
Alternatively a weak bracket may not support the weight of the countertop overhang.
Countertop overhang will depend on various other measurements such as the countertop itself and cabinetry.
Once your countertop overhang exceeds these numbers it will require additional support through corbels base cabinets or knee walls.
The allowable overhang with no additional support is no more than 1 3 of the depth of the countertop and not to exceed 15 total.
That said there are standard dimensions that can help guide you as you plan out your kitchen remodel.
So we are ok on the first criteria but we exceed the 1 3 criteria by four inches.
Amount of overhang you have is the most important factor to consider in deciding whether you need support brackets.
Overhangs greater than 15 require the installation of corbels.
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.
However you may need to install supports such as corbels or legs.
According to the marble institute of america you can safely overhang granite that is 1 1 4 thick up to 10 without supports.
However the cantilevered portion cannot be more than 1 3 the total width of the countertop.
As the chart indicated solid surface countertops may only overhang 6 inches without additional support.
The following recommendations help determine the needed support for quartz countertop overhang installation.
Even leaving your brackets weakly fastened leads to inadequate countertop support.
In conclusion the answer to the question how far can quartz overhang without support is.
Without any additional support solid surface countertop overhangs cannot exceed 6 engineered stone cannot exceed 14 and granite overhangs shouldn t be more than 10 without additional supports.