Decorative Concrete – What You Should Know
Though I normally espouse the wonders and joys of decorative concrete applications, I feel I should also inform about the other side of the coin: no matter what the color or stamp design reflects, it is still concrete. Your new patio may look like a gorgeous slate, but it is not. It is concrete. What does this mean? Well, it means that although concrete has limitless design options and can me formed into almost any design, mimicking many
other building materials; it does have minor limitations. A seasoned decorative concrete contractor knows this, and will install the concrete according to industry standards in order to best prevent cracks or color mishaps.
That said, these issues do arise on occasion. Let us begin with cracks in your brand new stamped concrete pool deck. Firstly, expansion joints are cut into the concrete to prevent cracks from occurring. However, everything from heavy loads travelling on the stamped concrete to land settlement underneath the concrete can cause a crack regardless of expansion joints. Proper cutting of the joints should alleviate this issue, and more often than not, it will. Secondly, when concrete cures it shrinks. This can cause cracks as well and even the most experienced concrete contractor cutting the best expansion joints in the world will not always win that battle. Lastly, a somewhat common “side effect” of stamped concrete is hairline cracks forming around the lines made by the stamping tools once the surface begins to harden. This is called “crusting” and typically will occur due to sun and wind. Obviously, sun and wind will quicken the hardening of the concrete surface. Another reason crusting occurs is due to the color of the concrete. Darker colors, as we all know, draw the sun’s rays and absorb the heat. Stamping tools with deeper grout lines for creating designs like random stone or slate patterns often aggravate the crusting. Many people feel that these hairline cracks add to the look of the stamped concrete design, giving it an “Old World” look. This aged appearance typically lends to the overall design. These imperfections are generally thought of as appealing. Although cracks can be repaired, the end result of the repair tends to be much more obvious than the unrepaired crack.
Now let us move on to coloring mishaps. Actually, “mishaps” is not the correct word here. A “mishap” would occur via accident. What I am referring to here is customer acceptance of the finished color on their new concrete. Depending on the method of coloring concrete (and there are quite a few) different factors come in to play in order for the concrete contractor to mix up the color chosen by the customer. However, as the customer there are a few things required of you in order to be sure you are receiving the color you want. A good practice would be to find photos of finished colored concrete patios, et. al. that show the color that you are striving to achieve, and submit to your contractor. However, understanding that there are variables involved with coloring or staining concrete that can affect the color outcome is key. Sometimes, the stars align and the concrete color turns out exactly as envisioned. And then there are times when this simply is not the case.
For instance, here are a few conditions that can, and most times will, cause color variations:
Customer is not available during color mixing. This will be a problem because if the customer is not present to approve color prior to installation, he/she may end up with a beautiful new colored concrete patio in a shade too dark or too light, or just not right. It is important for the customer to be present during color mixing to ensure happiness with the color.
Concrete job requires more than one truck load of concrete. Color will vary slightly from one batch to the next. This is to be expected and should be understood from the beginning.
Finished concrete color does not match sample chip or color chart. Never expect the final outcome to completely match up to the sample chip or color chart. Samples are just that: samples. Sample chips and color charts are meant to be more of a guide to the color. Mixing concrete color is not an exact science and should not be thought of as so. After all, even the best decorative concrete contractor in the area is only human!
Placing concrete at different ages. Placement of concrete at different ages will cause a slight color variation. This should be kept in mind during larger concrete projects, though it should not be more than a slight variation.