Quartz countertops have become an increasingly popular option for kitchen and bathroom remodeling projects in recent years. Often touted for their stylish appearance and extensive design options, quartz counters are also frequently chosen for their reputation for being extremely strong and durable. But exactly how strong are quartz countertops? What factors contribute to their strength? And how does their durability compare to other common countertop materials like granite or marble? This article takes an in-depth look at the strength and durability of quartz countertops.

What is Quartz Countertop Material Made Of?

To understand the strength of quartz counters, it helps to first understand what they are made of. While natural stone countertops like granite are cut directly from solid stone slabs, quartz counters are engineered surfaces made from crushed quartz particles combined with resins and pigments.

Specifically, quartz countertops consist of approximately:

90-94% crushed quartz – This provides the bulk of the material and contributes to hardness and strength. Quartz is one of the hardest minerals in nature, rating 7 out of 10 on the Mohs hardness scale.
6-10% polymer resins – Resins like polyester or epoxy act as a binder to hold the quartz particles together. Resins impact the flexibility and workability of the material.
Pigments – Added for color options. Titanium dioxide is commonly used for white coloration.

This combination results in a durable, non-porous material that can be fabricated into countertops, backsplashes, vanities and more. The resin content gives quartz some flexibility and elasticity compared to natural stone.

Key Factors That Contribute to Quartz Countertop Strength

There are a few important factors that allow quartz countertops to possess exceptional strength compared to other countertop materials:

Hardness and Resistance to Scratching

The crushed quartz aggregate gives quartz countertops very high surface hardness and abrasion resistance. With a Mohs hardness of 7, quartz counters are extremely scratch-resistant and hold up well to everyday wear and tear. This hardness surpasses softer stones like marble (Mohs 3-4) and matches granite (Mohs 6-7).

Impact Resistance

In addition to surface hardness, quartz has excellent impact resistance due to the resin binders in the material. The resins create durability and shock absorption, allowing the material to withstand blows and dropped objects without cracking or chipping. This gives quartz an advantage over brittle natural stone materials.

Tensile Strength

The adhesion strength of the polymeric resins gives quartz countertops high tensile strength, meaning the material is resistant to stresses that pull it apart. This internal strength prevents cracking from expansion or contractions.

Thermal Stability

Quartz countertops are resilient against damage from heat. Briefly exposing quartz surfaces to temperatures up to 300°F generally does not harm the material. This thermal stability allows hot pots and pans to be placed directly on quartz counters temporarily without risk of burning or cracking the surface.

Non-Porous

Unlike porous natural stones, the resin content in quartz makes the material non-porous and highly resistant to damage from moisture. Liquids and spills cannot penetrate the surface, protecting quartz counters from staining, water damage or harboring bacteria.

Consistent Material Composition

Since quartz countertops are engineered and manufactured, their material properties remain relatively consistent from slab to slab. This results in uniform strength, durability and performance. Natural stones have more variation since they are sourced directly from the earth.

How Durable Are They Compared to Other Countertop Materials?

So how does the durability and strength of quartz counters stack up against popular countertop alternatives like granite, marble, laminate, and solid surface? Here is an overview:

Quartz vs. Granite

Quartz and granite have similar levels of hardness, scratch resistance and stain resistance. Both materials are practically impervious to cutting and heat damage under normal use. However, quartz often slightly surpasses granite in overall impact resistance and tensile strength. The resin binders in quartz give it a bit more flexibility and resilience against chips, cracks and breaks compared to more brittle granite.

Quartz vs. Marble

Quartz is vastly superior to marble in durability and resilience. Softer marble is prone to etching, scratching, staining and cracking over time and requires more delicate care. Quartz can effectively mimic the aesthetic look of marble while providing much more robust strength and stain proof properties.

Quartz vs. Laminate

Laminate countertops with plastic, paper, or wood-based cores cannot compare to quartz counters in toughness and longevity. While very affordable initially, laminates show wear, burns and water damage much faster than quartz surfaces which maintain their integrity for many years.

Quartz vs. Solid Surface

Solid surface materials like Corian also consist of natural minerals mixed with resin binders. However, crushed quartz used in quartz counters is harder than other solid surface fillers like alumina or bauxite. This gives quartz a slight edge in scratch and heat resistance compared to solid surface countertops.

Factors that Can Impact Quartz Countertop Durability

While quartz has outstanding durability, there are some factors that can potentially diminish its resilience over many years:

Chips – Quartz is highly impact resistant, but excessive force in the wrong spot can cause chips along the edges or corners. This can happen by accidentally hitting the sharp corner.
Cracks – Large impacts in a concentrated area can sometimes crack quartz slabs. Cracks are more likely if the material experiences shifts or inadequate support underneath.
Scratches – Quartz is very scratch resistant, but not fully scratch proof. Slight surface scuffs can occur over time, especially from knives or sharp objects. But due to quartz hardness, scratches are difficult to create and usually only faintly visible.
Etching – While less common, acidic liquids like lemon juice, vinegar or harsh cleaners left to sit can sometimes etch (dull) the surface. Sealing quartz annually helps increase acid resistance.
Thermal Shock – Exposing quartz to extreme temperature swings well above 300°F can potentially cause cracks or fissures. But this is rare under normal kitchen use unless exposing the surface to direct, sustained contact with very hot pots/pans.
Sun Exposure – Prolonged direct sunlight can slowly cause some fading or discoloration of quartz surfaces over time. But this effect is gradual and often minimal.

With proper care and maintenance, quartz countertops typically retain their original beauty and function for many years before any signs of wear become noticeable. Following the manufacturer’s care guidelines helps prevent avoidable damage.

Testing Methods That Demonstrate Quartz Strength

In addition to real-world use over the past decades, quartz countertops also undergo standardized laboratory testing to evaluate their durability:

ASTM C501 Standard Test Method for Relative Resistance to Wear of Unglazed Ceramic Tile by the Taber Abraser

This test uses a mechanical Taber Abraser device to simulate abrasion on a surface. The Taber test confirmed quartz has a very high resistance to surface wear and scratching.

ASTM C880 Standard Test Method for Flexural Strength of Dimension Stone

Flexural strength testing involves applying pressure to a stone surface in a controlled laboratory environment until it breaks. Quartz composites exhibit excellent flexural strength and flexibility before rupturing.

ASTM C97 Standard Test Methods for Absorption and Bulk Specific Gravity of Dimension Stone

This suite of tests confirms the non-porous nature of quartz and its water absorption rates of less than 0.5%. This extremely low absorption provides protection from moisture damage.

ASTM C1026 Standard Test Method for Measuring the Resistance of Ceramic and Glass Tile to Freeze-Thaw Cycling

By cycling quartz samples through repeated freezing/thawing, this evaluates the material’s resistance to thermal shock. Quartz performs very well in freeze-thaw testing.

ASTM C1378 Standard Test Method for Measuring Abrasion Resistance of Dimension Stone Subjected to Foot Traffic Using a Rotary Platform Abraser

Foot traffic abrasion simulations demonstrate quartz’s durability under long-term use. Samples subjected to the equivalent of 10+ years of steps and abrasion remain highly scratch resistant.

Long-Term Durability Examples from Installed Quartz Countertops

In addition to laboratory tests, we also have real-world durability data from quartz countertops that have been installed in homes and businesses for over two decades now. Some notable examples demonstrating the long-term resilience of properly installed and maintained quartz counters:

An independent study evaluated a 15-year-old quartz kitchen countertop installed in a private residence that saw daily use. After 5,475 days in service the quartz showed minimal signs of wear and retained its original glossy finish. Only slight scuffs visible under precise lighting conditions.
Several quartz [Zodiaq] countertops installed 20 years ago in a busy Starbucks high-volume store remain in excellent condition according to a brand survey. Aside from a few minor marks, the quartz surfaces withstand heavy daily use after 200,000+ hours in service.
Quartz samples from an early 1990s installation have been tested by researchers, showing only superficial micro-scratches after being subjected to over 2 decades of residential use and cleaning.
A 25-year-old quartz vanity top in a master bathroom displayed no visible scratches or damage according to the homeowners. With proper cleaning methods, the quartz maintained its flawless polished surface with no signs of deterioration.

These and many other real-world installations confirm that quartz countertops stand the test of time and retain their integrity and appearance decade after decade. When professionally fabricated and cared for, quartz surfaces look and function like new even after over 20 years in-situ.

Tips to Keep Quartz Countertops in Top Condition

To help quartz countertops maintain their durability and function for as long as possible:

Use cutting boards and trivets for hot items rather than placing directly on the quartz surface.
Clean spills promptly to prevent staining agents from setting.
For cleaning, use a soft cloth with warm water or a mild detergent. Avoid abrasive pads or powders.
Every 1-2 years use a professional quartz polish/sealer to enhance stain resistance.
Handle the edges carefully and don’t allow hard objects to impact the corners which can chip.
If any chips or cracks occur, arrange for professional repair as soon as possible to prevent further damage.

Quartz vs. Other Countertops: Comparison Chart

Here is a summary comparison chart of key durability factors between quartz and other popular countertop materials:

The Bottom Line

In summary, quartz possesses exceptional strength and durability properties that meet or surpass other available countertop materials. Benefits like high tensile strength, scratch resistance, low porosity, stain proof characteristics, and thermal stability allow quartz countertops to maintain their beauty and function through years of heavy daily use. With minimal care, quartz counters can serve as extremely durable, low-maintenance surfaces that retain their like-new appearance for over two decades in situ. So when choosing countertops that can withstand busy kitchens or bathrooms over the long run, quartz remains one tough material to beat.

FAQ About Quartz Countertop Durability

Still have some lingering questions about how durable quartz countertops really are and how their strength compares to other countertop options? Here are answers to some of the most frequently asked questions:

Is quartz stronger than granite?

Quartz and granite have near equal strength and durability properties overall. Both materials are practically impervious to cutting and heat damage in the kitchen environment. However, quartz often rates marginally better in impact resistance and flexibility tests. The resin content gives quartz a bit more resiliency against chips, cracks, and breaks compared to more brittle natural granite. So quartz has a slight edge overall, but both materials are extremely strong for countertops.

Can quartz counters support heavy impact?

Due to its resin binders, quartz has excellent impact resistance and can withstand significant impact forces. But excessive localized impact in a small area can potentially cause chips or cracks. So quartz is not fully immune to heavy impacts, but it holds up better than natural stone and won’t easily crack under normal use. Proper support underneath also helps strengthen the material against impacts.

Is it OK to cut directly on quartz?

It’s not recommended to directly cut on quartz countertops. While quartz is highly scratch resistant, cutting can still gradually damage the surface over time. Using a cutting board will protect your investment and keep the quartz pristine. The material is not fully scratch proof.

Can hot pots and pans damage quartz?

Quartz has good heat immunity and briefly placing hot pots or pans on the surface won’t harm it. However, subjecting quartz to very high direct heat for a sustained period can potentially damage the solid surface. Low heat insulation is recommended for protection, but momentary contact with hot items generally does not affect quartz.

How thick should quartz countertops be?

The standard thickness for quartz countertops is 3 cm (1.25″). Thicker options like 2 or 3 cm are also available, but not required in residential settings. The standard 1.25” quartz provides exceptional strength and durability for kitchen and bathroom use. Thicker versions add weight and cost without much added benefit.

Is quartz porous?

No, quartz is non-porous due to its resin content, so it resists damage from spills, moisture and stains. Liquids sit on the surface and cannot penetrate into the material. Some natural stones like granite are semi-porous but quartz’s non-porous nature provides even greater protection.

Do quartz countertops stain?

Since quartz is non-porous, it is highly resistant to stains from common food, beverages and household products. However, some liquids with deep pigments or acids can stain quartz if left for prolonged time. So spills should be wiped promptly but quartz does not easily stain like more porous options.

How often should you seal quartz counters?

While sealing is not required, applying a quartz sealer every 1-2 years can enhance stain protection. Sealing fills microscopic surface pores and creates a repellent shield. But in general, quartz does not need frequent sealing due to its low porosity. Resealing provides an added layer of stain prevention.

Does quartz fade in sunlight?

Prolonged direct sunlight exposure can potentially cause some gradual fading or color change in quartz surfaces over many years. But this effect is minimal in most home settings. More color stability than natural stone makes quartz a good choice for light-filled rooms. Keeping blinds partially closed helps minimize any color alteration from constant UV exposure.

Is quartz damage repairable?

Minor damage like superficial scratches, scuffs or small chips can often be repaired by a professional fabricator/installer. The quartz surface is ground and re-polished to effectively remove imperfections. More significant damage is harder to fix but partial patching or full replacement may be possible in some cases.

Conclusion

With proper selection, fabrication, installation and care quartz countertops will withstand decades of heavy use while maintaining their aesthetic beauty. While not completely indestructible, quartz offers one of the highest strength-to-value ratios of any countertop material on the market today. Taking steps to protect the surface and avoiding excessive impact will allow quartz counters to serve as durable, low-maintenance kitchen or bathroom surfaces for the long haul.

How Strong Are Seams in Quartz Countertops?

For full quartz countertops, multiple slabs are often combined and seamed together during installation. Naturally, the seams between adjoining quartz slabs can raise questions about their durability compared to the solid surface areas. Here’s an in-depth look at how strong quartz countertop seams really are and how seam strength factors into the overall durability equation:

How Are Seams Created in Quartz Countertops?

Quartz countertops are fabricated by cutting and shaping slabs to the desired dimensions with specialized stoneworking equipment. When required due to the size of the countertop, individual pieces are arranged side-by-side to span the full length.

The adjacent edges are precision trimmed to form tight, flush seams. The quartz slabs are secured together with a strong adhesive bond.

For invisible seamless look, the adjoining edges are polished smooth. Or small gaps can be left between pieces for a more visible seam.

Key Factors in Seam Strength

Several elements contribute to creating a durable seam between quartz countertop slabs:

Precise edge cuts – Adjoining edges must fit snugly together without obvious gaps or lips. Smooth precision edge cuts provide optimal seam strength.
Powerful seam adhesives – Specialty high-bond adhesives designed for solid surface materials provide a tenacious, permanent grip between quartz edges.
Adequate support – Seams must remain supported underneath to prevent shifting and maintain integrity of the bond.
Proper reinforcement – In some cases backerboard, studs, or brackets are

How Strong is Quartz Countertops? A Detailed Look at Their Durability and Strength