Installing a new quartz countertop can instantly upgrade the look and feel of any kitchen or bathroom. With its durability, low maintenance, and customizability, quartz has become an increasingly popular choice for countertops in recent years. However, proper installation is key to ensuring your new quartz countertop lasts for years to come. One of the most important steps is selecting and properly using the right adhesive to adhere the quartz slab to the cabinet base.
Adhering a quartz countertop may seem daunting, but it can be made simple by following some key techniques and tips. In this comprehensive guide, we’ll walk you through everything you need to know about how to adhere a quartz countertop. We’ll cover choosing the right adhesive, prep work for the base cabinets, applying the adhesive, setting the quartz slabs, and finalizing the installation. With the right products, thorough preparation, and careful technique, you can end up with a flawless and durable quartz countertop installation.
Choosing the Right Adhesive
Choosing the proper adhesive is one of the most critical aspects of achieving a successful quartz countertop installation. Using the wrong type of adhesive can result in a weak bond and countertop failure down the road. Here are the key considerations when selecting an adhesive:
100% silicone adhesives specifically engineered for stone countertops are the best choice for adhering quartz slabs. Silicone adhesives are flexible and strong, allowing for a durable bond that accommodates minor shifts or movement. They come in squeeze tubes for easy application.
Avoid Mastics and Construction Adhesives
While mastics and construction adhesives may seem like an easier choice, it is best to avoid these options when installing quartz. Mastics do not provide a strong enough bond, while construction adhesives are rigid and can crack under pressure. Always opt for silicone adhesives made for stone and quartz.
Moisture-Curing vs. Neutral-Curing
Silicone adhesives come in two main varieties:
- Moisture-curing: These use ambient humidity to cure and adhere the quartz slabs. They can provide a quicker set time but may not work as well in dry environments.
- Neutral-curing: These rely on the mixing of an internal catalyst for the curing process instead of external humidity. Neutral-curing adhesives provide a stronger bond overall.
For quartz countertops, neutral-curing 100% silicone adhesives are the best choice for their superior bonding strength.
For a seamless look, choose a silicone adhesive that is color-matched to your quartz slab. The adhesive will be visible in the thin gaps between slabs, so matching the color prevents an unsightly contrast.
Preparing the Base Cabinets
Thorough prep work of the base cabinets is equally important for proper quartz installation. Here are the key steps:
Use denatured alcohol to clean the cabinets and remove any dust, oils, or debris left over from construction. All surfaces must be clean for the adhesive to bond properly.
Confirm that all cabinets are level and securely fastened to the wall and each other. Use shims if necessary to level any uneven areas. The cabinets must be able to support the full weight of the quartz without shifting.
Most installers recommend installing a 1/4”-thick underlayment, such as plywood, over the base cabinets prior to adhering the quartz. This helps level any irregularities and provides extra stability. Be sure to countersink any screws used to avoid bumps.
Dry Fit the Slabs
Do a dry fit of the quartz slabs on the underlayment prior to applying any adhesive. Ensure proper alignment at the seams and make any necessary adjustments. Mark the locations of the slabs with tape.
Thorough prep of the base cabinets and dry fitting the quartz slabs will make the final adhere process much easier.
Applying the Adhesive
With the right adhesive selected and base prepped, you can move onto the key step of applying the adhesive:
Follow Manufacturer Instructions
Be sure to closely follow the manufacturer instructions for the specific silicone adhesive product you are using. This includes proper surface prep, open times, cure times and more.
Apply Perimeter Dots
Run a bead of adhesive around the top perimeter of the underlayment using a zigzag pattern. Then make dime-sized dots of adhesive every 4-6 inches across the rest of the surface area.
Use Notched Trowel for Full Coverage
Use a 1/4” x 1/4” notched trowel held at a 45° angle to spread the adhesive evenly across the underlayment. This ensures full coverage between the quartz slab and underlayment.
Don’t Cover Entire Surface
The adhesive should cover about 80% of the surface area, leaving some gaps for air escape. Do not attempt to cover the entire underside of the quartz slab or it can cause peeking between the seams.
Applying the adhesive properly with adequate coverage but also proper gaps is critical for a successful quartz installation.
Setting the Quartz Slabs
With the adhesive applied, you can move onto setting the quartz slabs:
Lift Safely with Suction Cups
Carefully lift each quartz slab using suction cups and set gently into place, lining it up with the marked locations from dry fitting. Have helpers to lift the heavy slabs safely.
Apply Even Pressure
Once placed down, apply even pressure across the surface of the quartz slab to ensure good contact with the adhesive below. Use a pounding block and small rubber mallet to gently tap the slab into place.
Check for Adhesive Squeeze-Out
There should be some adhesive squeezing out around the edges of the quartz slabs when properly set. This indicates full adhesive transfer and bond. If minimal adhesive is visible, lift and reset the slab.
Clean Squeeze-Out Immediately
Make sure to immediately wipe away any excess adhesive squeeze-out with denatured alcohol. This prevents stubborn hardening of adhesive on the visible quartz surfaces.
Setting the quartz slabs properly with even pressure and cleaning excess adhesive right away will help create a strong, lasting bond.
Finalizing the Installation
Once the quartz slabs are fully set, there are just a few final steps to complete the installation:
Use Shims During Curing
Place shims between the slabs to prevent any sliding as the adhesive cures fully. Keep the shims in place for the timeframe recommended for the adhesive product.
Carefully inspect the seams between quartz slabs and use additional silicone sealant if any small gaps are visible. This provides added assurance against moisture penetration.
Use a belt sander to smooth any rough edges on the quartz countertop. Apply silicone sealant tohelp waterproof all seams and edges.
With these final steps finished, you can complete additional processes such as installing the sink and faucet before using and enjoying your new quartz countertop!
Below are some common questions about adhering quartz countertops:
How long does it take for the adhesive to fully cure?
This varies by product but most silicone adhesives take 24-48 hours to fully cure and bond the quartz slabs. Avoid excessive pressure on the countertops during this timeframe.
Should any supports be used underneath quartz countertops?
Yes, correct support is vital. Most installers recommend using a 3/4” plywood underlayment on top of the cabinets to support quartz slabs.
What’s the best way to cut holes for a sink in a quartz countertop?
Use a specialty diamond-tipped quartz cutting bit with a circular saw to cut any sink or fixture holes post-installation. Take safety precautions against dangerous silica dust.
Can you install a quartz countertop directly over existing laminate or tile?
No, for proper adhesion it is recommended to always remove existing surfaces and install on clean plywood or cabinets only.
How should seams between quartz slabs be handled?
After adhesion, seams can be filled with silicone sealant for water protection. Color-matched caulk provides the most seamless appearance.
Installing a quartz countertop adds beauty, durability, and style to any kitchen or bath. By using the proper adhesive, preparing your base cabinets, carefully applying adhesive, properly setting the slabs, and completing final installation steps, you can achieve flawless results. Just be sure to work carefully and methodically throughout the process. Patience and attention to detail will help ensure your new quartz countertop lasts for many years of stylish performance. With some diligence and these key tips, you can successfully tackle adhering quartz countertops.