A common question from homeowners doing a kitchen project centers around the amount of granite or quartz that is needed.
Many times, a homeowner will take the raw square footage of their countertop design and compare that to a slab. While slab size varies from product to product and producer to producer, the average granite slab will be 45-to-60 square feet, whereas the average quartz slab will be 45 to 50 square feet.
The assumption is that if a project is 40 square feet, then it will only need one slab as that easily covers the square footage requirement.
This is where we need to explain several aspects of stone cutting and design that will increase the raw material needs.
Probably the biggest impact of requiring additional slabs will be the veining within the piece. Veins are what give stone counters visual appeal. If you were to use a single slab for all pieces in a kitchen without accounting for the direction of veins, it will be very chaotic. Some veins will go left to right while others will be perpendicular. In general, you always want veining to be running in the same direction. This can require additional slabs to compensate for this need.
The next variable that will increase slab count on a project is the yield from cutting. Stone slabs aren't like a piece of plywood where you can just cut and have two adjacent pieces share an edge. Natural stone and quartz products have tension within the material, meaning that the sawyer will want a margin between pieces. Depending on the material and the saw, this margin can be as little as a half-inch, or as much as an inch. A 1" wide piece running the length of a slab is almost a full square foot of material.
Lastly, a good countertop fabricator and sawyer will want to minimize the number of seams or to have them located to reduce visibility. This will mean have pieces that aren't optimized for yield on the slab, but instead produce pieces to enhance how your counters look once installed.