How to Extend Quartz Countertop

Installing quartz countertops can greatly enhance the look and functionality of your kitchen. However, you may find over time that your existing quartz countertop is too small and you need more counter space. Thankfully, it is possible to extend your quartz countertop to add more room. Here is a comprehensive guide on how to successfully extend your quartz countertop.

Assessing if Extension is Possible

The first step is to determine if it is feasible to extend your current quartz countertop. Here are some key factors to consider:

  • Layout of the kitchen – Review the existing layout and available space. Ensure there is adequate room for the countertop extension. Measure to confirm an extension section can be accommodated.
  • Countertop type – Quartz is an engineered stone made of crushed quartz and resin. Verify your existing countertop is quartz and not another material like granite or laminate.
  • Edge profile – Check that the edge profile of your current quartz countertop is still available. This is important for a seamless look when joining to the extension.
  • Matching the quartz pattern – Quartz patterns can be discontinued. You’ll need to source a pattern that closely matches to achieve a uniform appearance. Discuss options with your countertop provider.

If space allows, your countertop is quartz, the edge profile can be matched, and a similar quartz pattern is attainable, then extension is possible.

Selecting the New Quartz Slab

Once you’ve determined extending the quartz countertop is viable, next select the new slab. Be sure to:

  • Match the thickness of the existing quartz as closely as possible. Standard is 3cm.
  • Match the edge profile of the current countertop exactly. Any difference will be noticeable.
  • Get a quartz pattern that is as close of a visual match as you can to the original pattern. Being off by even a slight variation in color or pattern can ruin the uniform appearance.
  • Buy a little extra quartz. It’s better to have leftover material than to come up short.

Work closely with your countertop supplier to source the right slab for the extension. Be picky to get as close of a match as you can.

Preparing the Existing Countertop

Before installing the new quartz extension slab, properly prepare the existing countertop:

  • Clean thoroughly – Use a degreasing cleaner and scrub well to remove any dirt, oil or residue. Rinse and let dry completely.
  • Sand the edge – Lightly sand the edge that will abut the new quartz piece using 100-grit sandpaper. This roughs up the surface for optimal adhesion.
  • Measure precisely – Carefully measure and mark the countertop overhang. This ensures the new section will align correctly.

Taking time to prep the existing quartz edge will lead to a tighter, more seamless fit with the extension.

Cutting and Installing the New Quartz Section

When ready to install, follow these key steps:

  • Mark the cut lines on the new quartz slab based on measurements.
  • Use a wet saw to cut the quartz precisely along cut lines. Quartz creates a lot of dust when cut – wet saws minimize this.
  • Dry fit the new quartz piece by placing it against the existing countertop. Check for any gaps and adjust as needed.
  • Clean the edge of the existing countertop and back of new piece with denatured alcohol.
  • Apply adhesive like polyester resin to join the pieces. Spread evenly.
  • Clamp together tightly and allow the adhesive to fully cure as directed, usually 24-48 hours.
  • Once cured, remove clamps and clean up any excess adhesive squeeze-out.

Take great care when cutting, test fitting, gluing and clamping to achieve a flawless finished extension.

Shaping and Finishing the New Section

For a complete quartz countertop extension, finish by:

  • Use a router to shape the edges to exactly match the current countertop. Take your time for perfection.
  • If needed, shine the surface with a polishing compound to restore sheen.
  • Seal the seam and new front edge with a silicone sealant designed for quartz.
  • Give the entire extended countertop a thorough cleaning with a stone-safe cleaner.

With attention to detail on the final shaping and finishing steps, your extended quartz countertop will look amazing and function seamlessly.

Maintaining the Extended Countertop

To keep your expanded quartz countertop looking like new:

  • Use trivets and hot pads when placing hot items on the surface. Rapid temperature changes can damage quartz.
  • Clean regularly with a gentle stone cleaner and soft cloth. Avoid abrasive cleaners.
  • Reseal the seam and front edge every 1-2 years with a silicone sealant.
  • Avoid using the countertop as a cutting surface. Use a separate cutting board to prevent scratches and nicks.
  • Immediately wipe up any spills, especially juices, vinegars, wines or harsh cleaners. Acids can etch quartz.

With proper care and maintenance, your extended quartz countertop can stay gorgeous for decades.

FAQs About Extending Quartz Countertops

Can you extend a quartz countertop yourself?

It is possible for an experienced DIYer to extend a quartz countertop on their own. However, it requires specialty tools like a wet saw and router. The lamination process with adhesive also has a learning curve. Unless you have worked extensively with quartz, it is advisable to hire a professional installer.

Does the quartz pattern need to be exactly the same?

It is best to match the pattern as closely as possible. However, slight variations in the quartz patterning and colors are generally acceptable if the overall look is cohesive. The seam may be more visible if there is a drastic difference between old and new quartz.

Should you use epoxy or silicone to join quartz seams?

Specialty adhesives like polyester resin epoxy provide the strongest bond when joining quartz pieces. Silicone sealant is recommended for sealing the seam for water protection after installation. Using only silicone to join quartz will likely lead to seperation over time.

Can you install new quartz right over existing quartz?

It is not recommended to overlay new quartz directly on top of old quartz. For best adhesion and a flawless finish, the existing quartz edge needs to be prepared via cleaning and sanding prior to attaching the new slab.

Is there a seamless look when extending quartz?

With meticulous cutting, sanding, fitting and bonding, the seam between old and new quartz can be made very inconspicuous. Matching the edge profiles exactly helps create the most seamless transition. Proper finishing and sealing minimizes the visibility of any seams.


Extending existing quartz countertops is an effective way to gain more workspace without undergoing a whole kitchen renovation. With proper planning and preparation, the right quartz selection, precision cutting and installation, plus final shaping and sealing, your expanded quartz countertop can look and perform beautifully. Just be sure to maintain it properly for long-lasting durability and enjoyment of your upgraded kitchen.