Concrete & Cement Diamond Polishing













Diamond polishing a concrete floor is a multi-phase operation that consists of refining the surface of a concrete slab with progressively finer diamond grit. The diamond grit is contained in special polishing discs and buttons made of metallic, ceramic or resin matrix. The diamonds, being the hardest material in nature will abrade the concrete, producing a finer "scratch pattern" at each pass. The final grit leaves and invisible scratch pattern, so fine that the surface feels extremely smooth and acquires high reflectivity. Nevertheless, the scratch pattern is there, giving the surface a better grip and making the polished finish much safer than any epoxy coating on the market.


GRINDING - When restoring old concrete (or when achieving a particular look, for example a "terrazzo" finish) the first step is grinding the surface to remove the top layer of concrete called "cream". This operation exposes the small stone aggregate contained in the concrete mix. The more the surface is ground, the larger is the size of the exposed cobbles. The grinding is usually performed with 30 grit metal bond diamond buttons, which leave a quite heavy and visible scratch pattern. The grinding marks are removed with two additional grinding steps, the 70 and the 120 grit. This last one is barely visible to an untrained eye.


HONING - The next step, called "honing" further refines the surface using transitional diamond tooling, usually ceramic matrix plucks. The final honing grit leaves a smooth, but not quite reflective surface. After this phase  the floor can be colored and sealed, or polished to a higher grit.


COLORING AND DENSIFICATION - After the honing stage and before proceeding with the final polishing steps is when color dyes/stains and densifier are applied. Dyes and stains for polished concrete are especially formulated to be penetrate such dense surface. The use of standard concrete stains (like acid stains) will most likely result in poor aesthetics. The "Densifier" is a water based liquid containing lithium, potassium and sodium silicates. When applied to the concrete surface it penetrates and the silicates chemically bond to the concrete molecules, strenghtening the slab and forming additional surface between the pores. This process allows for achievement of higher sheen but also dramatically  increases the performance of concrete. For these reasons the application of densifier can be used stand alone as remediation for severe cases of efflorescence.


POLISHING - The last phase is the actual "polishing", when the surface is refined to reach reflectivity. The degree of reflectivity can be adjusted to the individual preferences. Most concrete achieves a quite high reflectivity already at 800 grit, which is also the standard final polishing step for commercial floors open to public. The actual slip coefficient  varies from slab to slab, so the only way to be exactly knowing is to measure it.


SEALER - As the polishing is completed, a hybrid silicates sealer is applied to enhance the sheen and protect the floor. The sealer can be buffed/burnished  with diamond pads to achieve the highest gloss and reflectivity.


EQUIPMENT - Modern concrete grinders/polishers are heavy duty machines equipped with a "planetary" main wheel and rotating heads carrying the diamond tools. Like in our Solar System, the heads (Planets) rotate around a common center (Sun) and also on their own axis. This planetary motion of the heads, in conjunction with the weight of the machine is what really allows for polishing on concrete. Not all machines on the market perform the same. Our Superabrasive machines are among the most advanced on the market.

DelGrosso Design specializes in Concrete and Cement Floors Diamond Polishing


Our main installations are:


- Concrete slabs grinding & diamond polishing.

- Cement topping installation and polishing.

- Self leveling cement topping installation.

- Outdoor concrete mechanical restoration.

- Concrete/Cement custom coloring.

- Floor Art and graphics' stenciling.

- Restoration and maintenance of polished floors.


We offer our services to private residential clients, as well as commercial, industrial and public sector clients.

COMPANY HISTORY - The company was founded in California in 2002 by Andrea DelGrosso after more than 10 years of being in business in Northern Italy (Lake Como), where he was born and raised. Andrea's (his first name being just like Bocelli's, the Italian opera singer) construction background goes back to when he was 16 and, following the footsteps of his grandfather and his dad, started building with stone and concrete. Over the years he developed his own artistic eye, as well as a strong sense of business. In 2002 he moved to San Francisco Bay and he established his company in Santa Rosa, where he resides with his family.

OUR WORK - All our work is hand-made with passion and superior mastery. Going through our website and pictures' gallery you will see how unique our projects are. They are always developed with and for our clients, in this way achieving a complete customer satisfaction. Our dedication to our customers shows in the details of every project. Our goal is to always exceed our clients' expectations. Our Unique designing style is rich with Italian and Mediterranean touches. Our values of honesty, reliability, great performance and clean look, makes of our company "one of a kind". Over the years we have built a solid reputation based on all these facts. Besides homeowners, since 2008 we are also serving commercial and industrial clients, such as retail stores, offices, and schools. Our philosophy is to continually grow the company performing excellent and unique work and offering a superior customer service.

LOCATION - DelGrosso Design is located in the heart of the  "Wine Country", in the world famous Valley of the Moon, between Santa Rosa and Sonoma. Besides Sonoma and Marin Counties, we also now operate in the City of San Francisco and in Lake, Mendocino and Napa counties.


In our neighborhood  we serve the towns of Santa Rosa, Kenwood, Glen Ellen, Sonoma, Rohnert Park, Cotati, Petaluma, Penngrove, Sebastopol, Windsor, Healdsburg and Calistoga.


Given the high amount of requests we now also serve Napa, Vallejo, American Canyon, Novato, San Rafael, Kentfield, San Anselmo, Greenbrae, Corte Madera, Mill Valley, Fairfax, Nicasio Valley, Sausalito, Graton, Forestville, Guerneville, Rio Nido, Occidental, Valley Ford, Cloverdale, Ukiah, Middletown, Cobb Mountain, Sea Rench, Gualala, Philo and Annapolis.


If you have a unique project and you want to inquire with us on pricing and availability, please email us by filling in the form at the "ESTIMATES" page of this website.



Hand-polishing techniques were used since the beginning of human civilization on artifacts and objects. About 3,000 years ago the Greeks started using polishing techniques on temple floors and columns. The ancient Greek society was the first  culture specifically creating architectural structures with a polished finish purely for aestherical purpose rather than practical. During the following centuries with the expansion of the Roman Empire the polishing techniques were used all over Europe in cathedrals, king's palaces and private residences as a "Status Symbol". Although the Romans invented Concrete more than 2,000 years ago, floors where were made of marble or other types of natural stone. The polishing process was completely hand-made and needed a large amount of labor and time to be completed.


In 1586 the "Arte dei Terrazzieri" in Venice was the first artisan association to implement and write down specific rules on how to polish the "Venetian Terrazzo". This floor consisted of colored marble chips set by hand in a mosaic design, then polished to a smooth finish. Until the 1970's the binding material was a lime based mixture, of which the formula remained unchanged for centuries. In the 1970's new cementitious glues started being produced and used to provide stronger cohesion of the marble chips.


Only a few decades ago the technological improvements in concrete mix formulation and diamond tooling made possible the polishing directly on concrete slabs. Grinding machines originally built for stone polishing were redesigned and diamond tooling was engineered specifically for concrete refinishing. Modern grinders/polishers are heavy duty machines engineered for work on a very large variety of concrete and cement mixes. Most important is the proper matching between concrete hardness and the diamond tooling used (soft, medium, hard, extra hard) surfaces.The proper match increases the performance of the tooling and also the precision of the results.



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DelGrosso Design is a GREEN COMPANY and proudly sustains and encourages the practice of Green Building in our territory. All our installations meet the BAAQMD (Bay Area Air Quality Management District) which in January 2011 restricted in its territory the admissible VOC (Volatile Organic Compound) contained in any product on the shelves to 100 VOC or less. As consequence some of the products previously available on the Bay Area stores are now outlawed, pushing many manufacturers to come out with new VOC compliant products. This step is vanguard in the whole nation (with the Los Angeles District which adopted these regulations a few years earlier). In addition to this, DelGrosso Design adopts green building practices at many different levels, including the minimizing and the recycling of construction debris.


Here below some of the facts that makes our POLISHED CONCRETE AND CEMENT FLOORS among the GREENEST in the trade:


  • By restoring your existing concrete a lot of energy is saved by not demolishing, hauling and re-processing materials

  • All products from dyes to densifiers and sealers are water based and do not derive from petroleum (unlike epoxy, polyurethane and other plastic materials)

  • Energy (and cost) is saved by needing fewer and lighter maintenance

  • The higher reflectivity reduces up to 50% of the necessary lighting (most effective on commercial floors)

  • The dense and smooth surface is virtually dust, allergens and mold resistant, reducing if not eliminating the need for cleaning and disinfecting with harsh chemicals and/or processes.

  • The longer durability (up to 4 times longer than standard commercial flooring covers) reduces the energy (and cost) for rebuild.

  • Concrete and cement retains heat longer in cold weather and stays cooler in warm weather, reducing the amount of heating and cooling energy necessary in most households.

  • Our cement coatings utilize sustainable materials abundant in Nature, as limestone and sand, unlike other materials, as for instance wood, which require the harvesting of forests, sometime endangered and protected.


Despites in the Bay Area products with VOC higher than 100 are banned from shelves, it is very easy and legal to buy these products from out of State and online stores. However, the use of these products is illegal in the San Francisco Bay Area. Require your contractors to respect these laws and verify the VOC content of the products applied on your premises. Please note that VOC COMPLIANT does not mean "no bad odor" or "safe to handle". Most products for concrete and polished concrete are meant to be used by professional and trained personnel only. As a general rule, most water based product are quite safe and with very little toxicity, while solvent based products can be more harmful,  most often need to be handled by wearing respirators and gloves and empty containers properly disposed. Most local administrations in the Bay Area enforce very strict regulations on disposal of hazardous materials in storm drains and fines up to $30,000 can be assessed to infringers by local law enforcement.



 Many are the uses of concrete. Most modern buildings are constructed on concrete foundations and footings, and many structures in the landscaping surrounding buildings are made of concrete. Today concrete floors are becoming the standard for residential and commercial construction.


Concrete is a mix of Portland cement , gravels and water, the latter ones being materials readily available in most places on Earth. Portland cement is a fine powder derived from the mining, crushing, cooking and refining of natural rocks present in specific regions. Portland cement is packaged in bags and distributed all over the world to be mixed into concrete. Concrete is easily poured into pre-fabricated forms to make footings, slabs, walls, objects, high-rise buildings, bridges, furniture and more. Concrete was discovered more than 2,000 years ago by the Romans, who used it to build roads and temples. It is believed to be one of the reasons that made possible the expansion of the Roman Empire to the known extents.


Concrete becomes stronger and stronger when compressed together and this is the property that makes it so good for construction. In other words, a concrete footing will become stronger and stronger as the structure is built above and more weight added on top, without exeeding the breaking point. The weight of the structure above "compresses" the concrete, making it stronger. On the other side, concrete does not have high tensional strength and tends to separate fairly easily when pullied apart. For this reason concrete structures need to be  "re-enforced" with steel bars or other systems. Steel has a high tensional strength when stretched. So you see how concrete and steel together make a structure able to withstand incredible stress, like in highways' bridges and high rise buildings.


Decorative concrete is a branch of concrete construction that specializes in concrete structures and objects meant to have, besides structural purpose, a pleasing appearance; in other words an  aesthetically appealing look.


In the last three decades an incredible progress has been made in this field. A great number of  products has been engineered for adding color, strength and texture to concrete. The "finishing" is the phase in which a specific look is achieved. The finishing on concrete is performed by artisans (concrete finishers) who master the different techniques. Years of experience are necessary to become a good concrete finisher.


The finishing on concrete must be performed in a specific time frame during the pouring, after the concrete is stiff enough to be worked and maintain the shape, but before is completely set. This window of time is usually very narrow, and this makes so difficult the achievement of high quality results. Modern technology supplies an array of chemicals, fortifiers, admixtures and aiding products to help achieving the incredible looks we see on modern high-end concrete. In the last decade the market has also seen the introduction of many products to repair, restore diamond polish and protect concrete, as well as colors and stains that can be applied after the concrete is completely set.


Sometimes it can be very difficult for an home or business owner to identify which one direction to go and which finish to select for their concrete project. All our clients can count on our multi-facets expertise in concrete construction and on our guidance through this crowded and sometime complicated world. Our knowledge goes beyond the mere use of color pigments and sealers, and is more comprehensive, including many of the structural details (for example control joints design, concrete mix design, steel reinforcement design...) that are so often under estimated or even unknown to many operators in the decorative concrete business.