A common misconception among customers, general contractors, and architects is confusing a sealed concrete surface with a polished concrete finish due to its shiny appearance. Observing a high gloss sealer on a ground concrete slab often leads to the false assumption that it is polished concrete – which it is not. This confusion represents one of the most frequently misrepresented terms in our industry. The differences between sealed and polished concrete are substantial, especially in terms of the process, duration, and cost. However, we provide both services for our customers’ convenience.
Grind and Sealed
Often referred to as ‘Grind and Seal’, this process starts with cleaning the concrete and letting it dry. Then, a thin layer of acrylic, epoxy or urethane sealer is applied to the concrete, much like painting. When dry, the surface appears shiny due to the thin layer of sealer that has filled the concrete’s pores.
Some sealers are specifically engineered to prevent moisture penetration under finished floors. Sealed concrete is commonly used in low-cost, low-traffic areas such as stairwells, IT rooms, and file storage areas. However, a major disadvantage of sealed concrete is its susceptibility to quick wear and tear, particularly from heavy traffic or impact on the slab. Resealing is required every few years as the sealed concrete surfaces wear out over time, reverting back to raw concrete, especially in high-traffic zones. It’s important to note that a sealed concrete finish never achieves the same clarity or vibrancy as properly polished concrete.
Pros
Much less labor intensive
More cost effective – often half the price
With the right product and surface preparation– will not harbor bacteria
Epoxy and Urethane sealers are UV and abrasion resistant.
Cons
Ongoing costs which requires resealing and maintenance.
Works best in low traffic areas such Storage and IT rooms
Not always moisture tolerant, moisture testing and mitigation may be required.
Low grade sealers can scratch easy and damage due to heavy traffic /impact on
Polished concrete finish with aggregate exposure.
Polished Concrete
The process of creating polished concrete floors involves multiple stages of grinding the concrete surface with increasingly finer diamond tooling until it becomes completely smooth and free from scratches. To harden and fortify the concrete surface, densifiers are used. Once the desired level of polish is achieved, seal guard products are applied and then burnished into the concrete. During these grinding stages, any control joints, cracks, spalls, and other flaws can be filled and repaired, resulting in a seamless floor. The grinding process also reveals various aggregate and concrete features that have been hidden since their installation, resulting in a unique and aesthetically pleasing floor.
Burnishing is the final step in the polishing process. Its power lies in bringing out the glossy shine of polished concrete. It is not a sealant.
The process of burnishing concrete involves the use of high-speed burnishers, designed to heat, melt, and buff the seal guard treatment into a polished concrete surface. Sealants like the RetroPlate System safeguard concrete floors against stains and dusting, and when burnished, they produce a high gloss and shine.
The finish of the floor can vary from flat, matte, satin, semi-polished, to a highly polished glass-like appearance, depending on the grit level used. The shine levels of your floor can range from very low to very high, contingent on the number of steps taken to cut the concrete.
Polished concrete works by densifying and sealing the surface, turning a permeable concrete floor into a consolidated one that is dense enough to resist water, oil, and other contaminants, preventing them from seeping into the surface. Despite its shiny appearance, polished concrete does not result in a slippery floor. In actuality, the advantages of mechanically grinding and flattening the floor ultimately enhance the friction coefficient compared to standard concrete. Oftentimes, polished concrete surpasses the floor standards set by OSHA.
Polished concrete is an excellent choice for areas with high visibility and heavy foot traffic that need to be both functional and attractive, while also being durable. It’s a great fit for open office spaces, lobbies, cafeterias, conference rooms, corridors, restrooms, chemical storage areas, warehouses, manufacturing facilities, educational institutions, retail outlets, restaurant dining areas, grocery stores, medical facilities, large retail stores, hotels, car showrooms, municipal buildings, apparatus bays, and any other space you can envision!
Pictured above is a grind and seal.
Pros
One time application and minimal maintenance.
Long life Cycle
Safer surface- increased slip resistance exceeds OSHA standards
High Durability and Abrasion resistant
Reflective surface maximizes available light- saving energy
Resistant to moisture transmission issues
Lower initial costs compared to traditional floor coverings
Sanitary and does not harbor bacteria.
No VOC
Chemical and thermal shock resistant.
Cons
Hardness- The strength and durability of this material can also be a drawback as the surface is very hard, so it won’t cushion or “give” under feet.
Cold- does not retain heat very well.
Loud- floors can be loud like ceramic tile, natural stone flooring and hardwood
Moisture can be a problem if the floor is not finished properly by trusted polished concrete installer.
Before your slab is poured, it’s crucial to understand the differences between various concrete finishes and conduct thorough research. If you’re considering a mechanical polish, make sure both your builder and concrete contractor are aware of these differences so they can plan and pour accordingly for your desired finish.
When obtaining quotes for polished concrete and grind and seal services, ensure you’re comparing like with like since numerous variables can affect the comparison – such as the machinery used, number of passes, the contractor’s experience, and the type and quality of materials used. Concrete polishing is more labor-intensive and hence more costly than grind/seal or burnished concrete. If you’re drawn to the look of polished concrete but need a more budget-friendly alternative, we suggest considering a high-quality sealed concrete finish that will be suitable for your specific environment.