Here are a few key terms to help you better understand the lingo we use when describing your driveway.
Concrete: Like any good building, our company is built on a foundation of concrete. But what exactly is concrete? Plain grey concrete is made up of four ingredients: Portland cement, water and both fine aggregates (sand) and course ones (gravel). It’s important to understand that there is a difference between cement and concrete. Cement is one element of concrete, but it’s an important one. If concrete is bread, then cement is the flour. For more information, see our "What is Concrete" page.
Pounds per Square Inch (PSI): This refers to the amount of pressure per square inch that concrete can withhold before cracking. We only use commercial grade concrete that is 4,000 PSI as anything less than that will often times lead to the development of cracks in your concrete. Anything more, such as 5,000 PSI cures out too fast before the finish can be applied in a cost effective manner.
Colored Concrete: Plain grey concrete can be tinted to a wide variety of colors. The most effective way to add color to your concrete is by our concrete suppliers during the mixing process at their plants. This is known as “integral color”. Colors are added via the cubic yard of concrete with lighter colors costing less and darker colors more. Check this link to see typical colors you can choose.
Stamped Concrete: Hemma uses forms that we have in stock to affect the finish of poured concrete. Our experts in this technique can allow our clients to enhance the look of their projects. The stamping can be done on the apron, along the edges or borders, across the poured area called bands, or throughout whole job. Different stamps can be used to create visually stunning works of art. Ask your estimator for the patterns we own, and explore patterns to choose from here.
Stamping Process: Once concrete is poured and at the exactly correct time, a “release” is applied manually (sometimes referred to as “hand seeded”) across the areas to be stamped. The release allows the stamps to not stick to the concrete, hence the name, and typically has a secondary color to create a stained antique look. The large mat-like stamps are laid out as required and tamped down manually by are technicians. Again, at the exact right time, the stamps are carefully removed as to not damage the concrete. Once washed off, a sealant is typically applied to the pattern to achieve the final glossiness desired. Sealants can be water or solvent/oil based with the water based ones giving a duller gloss and the oil based ones giving a higher gloss finish. Additives to the sealant like Shark Grip can also be included to make the stamped concrete less slippery thereby safer. Sealants also require re-application as time in the sun and weather will dull their sheen creating future on-going maintenance costs.
Exposed Aggregates: At the higher end of the cost spectrum are exposed aggregate pours where common aggregates (gravel) or more artistic ones (pea gravel, Indiana pea gravel, black beauty, etc.) are added to the concrete. Color is also integrated into the mix as well. Most often the aggregates are added at the mixing plant, and, in order to get the desired look, may also be hand seeded after the concrete is poured. After the hand seeding, a retarder is applied that basically stops the concrete from curing. Depending upon how much of the aggregate is desired to be seen, different retarders can be applied (e.g., 75, 100, 125) with the higher numbers allowing more of the aggregate to be exposed. After the retarder is applied, and the correct amount of time has lapsed, the retarder is washed off revealing the beautiful finished product. Sealants are also applied much like those described in the Stamping Process section. Here are some examples of exposed aggregate finishes
Control Joints: Joints are indentations in the concrete that help to relieve stress on the concrete and prevent random cracks on the surface of the concrete.
The natural movement of concrete leads to restrain and eventually cracking. Restraint simply means that the concrete is not being allowed to freely shrink as it dries or to expand and contract with temperature changes or to move with the movement of the underlying base. Even if the concrete does crack, the joints help to limit the damage and ensure the cracks occur in straight and regular lines.
All of Hemma’s joints are hand-tooled, which allows us to provide a better looking and longer-lasting joint than those installed by a concrete saw. In a regular driveway, joints should be placed between 8-12 feet apart. Hemma Concrete typically puts joints about 10 feet apart. Control joints should be approximately one quarter of the thickness of the concrete. Because all Hemma driveways are four inches thick, our control joints are at least one inch deep. In most cases, we make them up to 1.5” deep to increase their effectiveness.
Finishing: We add a light broom finish on our new concrete driveways in order that your new driveway is not slick when wet. This is because the small grooves in the surface help to wick water off the surface. Not only that, but it gives the driveway a finished and artistic look. Steeper driveways will get a heavier broom finish.
Picture Framing: At Hemma, the edges of each section of concrete on your new driveway have a 2” smooth trowel finish providing a ‘picture frame’ around each section. The ‘picture frame’ is not intended to improve the strength or quality of your concrete. It is there to give your new driveway a more attractive and a more finished look.
Reinforcement: In keeping with Hemma’s No. 1 ranking for quality, we offer three entirely different kinds of reinforcement: steel rebar, integral fiber, and wire mesh. Although most people are familiar with steel rebar and wire mesh as a means of reinforcement, fibers are the latest technology in concrete reinforcement. These fibers are mixed into the concrete at the concrete plant to achieve maximum fiber distribution, and prevent the need and added costs for wire mesh. This spreads millions of fibers in the concrete, which serves to help prevent cracks. This is why Hemma Concrete is able to guarantee all concrete work for a full five years and why we’re able to stand by that warranty without hesitation.