Common Myths
We feel that the concrete world would be a better place if everyone did concrete right. As such, for the benefit of the world and the reputation of our industry, we are listing out popular myths followed by the truth. Please ensure that your concrete company reads, understands and executes based on the facts and not on common myths. Here we go:
Myth #1: You should specify a concrete mix by the number of yards needed.
Fact: When ordering concrete, one should specify the intended application so that the concrete mix meets the performance expectations. Concrete is a mixture of water and cement. This ratio of water to cement plays a big role in determining the strength of the concrete.
Myth #2: Adding water to the concrete mix is the only way to increase slump (i.e. how wet or dry your concrete order will be).
Fact: There are many ways to increase and decrease slump other than adding water. By adding one gallon of water to a cubic yard of concrete, unintentional consequences will arise. More specifically, this will reduce the compressive strength of the concrete by 150 to 250 psi, waste ¼ bag of cement, and increase the chance for shrinkage and ultimately increase the chance of hair-line cracks. Slump can be adjusted while properly maintaining the correct water to cement ratio. Slump should be measured and corrected throughout the entire pour process.
Myth 3: Curing concrete means letting it dry.
Fact: Concrete needs water to continue to hydrate and gain strength. As cement hydrates, new chemical compounds form in the fresh concrete. The longer you cure concrete or the longer you allow it to take to dry, the stronger and more durable the concrete will become. The loss of water prevents the process of hydration. Proper curing requires the right amount of water, surface moisture, and temperature. All of these factors can and should be controlled throughout the work day.
Myth 4: No bleed water and a successful footprint test means the day was a success.
Fact: The finishing process is an art that takes experience to ensure that the process does not begin too early or too late. Blistering, dusting, crazing, delamination, and bleeding may still occur when it is not visible. In summary, be sure that the bleeding process has stopped before you start the finishing work. It is also important to use good judgment when selecting the materials you use during the finishing process.
Myth 5: No blankets are needed if calcium chloride is in the concrete. Calcium chloride is an anti-freeze agent.
Fact: Calcium chloride is an accelerator only. The concrete can still freeze. The concrete will gain strength slower in low temperatures. The concrete must be protected until it reaches the minimum strength of 500 psi. To avoid problems, you should cover the concrete with curing blankets.
Myth 6: You can pour concrete on a frozen ground without precautions because the concrete will heat the soil.
Fact: It is critical that precautions be taken when pouring concrete in adverse conditions. Never place concrete on a frozen ground. The rapid cooling of the concrete will interrupt the ability for the concrete to harden properly. To do it right, the soil temperature should be close to the temperature of the concrete at the time of the pour. Be sure to thaw the ground before proceeding.
Myth 7: Reinforced concrete won’t crack.
Fact: Structural reinforcement does not prevent concrete from cracking due to volume changes. Rebar will actually act as a restraint and increase the chance of concrete cracking. The purpose of rebar and wire mesh is to hold the concrete together in the event that the concrete does crack. Rebar and wire mesh will allow the concrete to withstand higher tensile loads. Concrete volume changes from temperature and moisture cycles is to be expected during the life of concrete.
Myth 8: Fresh concrete that is flat and level will remain flat and level after hardening.
Fact: Concrete can change shape while hardening. Temperature changes can cause horizontal movements and cause curling that lifts up the slab edges at joints and cracks. Problems might also arise when the temperature at the bottom and top of the slab is different. Take precautions to control this risk.
Myth 9: Concrete is impermeable.
Fact: Even the densest concrete is somewhat porous. “Solid as concrete” really means “as porous as a sponge”. In fact, liquid and vapor can pass right through it for several hours to several months. Offset this risk by placing a vapor retarder directly under the slab. Make the slab more water tight and run a lower water to cement ratio.
Myth 10: The higher the concrete strength, the more durable the concrete will be.
Fact: Compressive strength alone does not determine the durability of concrete. There are other factors that are actually more important. The following factors will play a role: corrosion of reinforced steel, exposure to freeze/thaw cycles, sulfate attachments, and exposure to moisture.
In summary, get educated, ask questions, and don’t take short-cuts. If we mess up, we will take responsibility for our failure. Our goal is to enhance the industry by dispelling common myths and consistently implement best practices.
Common Questions
What do you do with a dog house?
If a dog house is in the area where you want concrete, we will remove it until after the project is completed and the concrete has had seven days to cure.
What is the typical patio size?
The design of your patio is only limited by the amount of space you have and your imagination. We can build curves with a nice rounded radius, half-moon steps, benches, and even wood-like bridges. The configuration and design options are almost endless. Or, you can choose a very simple, functional, and economical square patio.
We do suggest considering how you want to use the space and what your budget is. Will there be furniture? How it will be placed? Some recommend having three feet of space from the furniture to the edge of the concrete. So knowing what outdoor furniture you will use, and how it will be placed, could be a good start to planning your patio size. Also, think about keeping the patio size proportionate to your house. However, it’s really up to you to decide what criteria you use.
What height are steps?
Anywhere from 4-8 inches high and typically 12-36 inches wide.
What do you do if there are stumps?
Stumps need to be removed before laying concrete. Over time, stumps deteriorate and rot which could cause cracking and settling for the concrete. Removing stumps beforehand is cheaper than having to redo concrete later! We can remove bushes, small trees and stumps for you.
What do you do with sprinkler heads?
It is best not to have any part of a sprinkler system located under concrete in case of problems. If there’s ever a malfunction with your sprinkler system, you don’t want to go looking under concrete! Our company can make recommendations in this area and execute the recommendations upon request.
How do you handle rain gutters and PVC pipe drains?
It is best that drains not point where water flows directly onto concrete areas, as it can damage concrete over time. Depending on your situation, drains my need to be redirected and/or downspouts created to go under concrete. Solutions vary depending on your specific drainage needs. Our company will make recommendations and complete this work if approved.
What do you do after concrete is poured?
You will need to keep the surface moist for at least the next seven days. Most of the concrete curing will occur over the next 30 days. Otherwise, shading the slab with burlap, straw, or a plastic blanket will help.
What is the cost difference between stamp color and regular?
Regular concrete is typically a 1-2 day process; whereas, stamped/colored concrete is typically a 4 day process. Therefore labor is almost doubled and then you have the stamp rental and we must buy the color. The price of the color is dependent on how dark the color is. A darker color is more expensive.
What do you do if stamped concrete color fades?
Stamped concrete can last for decades. If a stamped patio has faded over the years, cleaning and resealing it can brighten the color and will often be enough.
Many suggest cleaning and resealing stamped concrete every 2-5 years.
With our stamped concrete, a base color is mixed into the concrete itself and then a release color is applied on top. Due to the color being mixed into the concrete itself, the surface will still look aesthetically pleasing if a chip occurs.
Will stamped concrete be slippery when wet?
Stamped concrete has texture to it, which makes it more slip-resistant than some other options. However just like stone, it can become slippery when it gets wet. Topical sealers can also make it more slippery depending on what type of sealer is used or how thick it is applied.
How far apart are concrete joints?
Concrete joints allow the concrete to expand and contract, placing less stress on the concrete surface. This helps prevent cracking. Joints are usually spaced 10 to 15 feet apart. Typically, stress lines are placed in areas that are prone to crack.
Should I do steps or a raised patio?
Best Denver Concrete almost always suggests doing steps instead of a raised patio, as it is much more cost effective. A raised or lifted patio is much more difficult and takes more labor, materials and strategy to successfully complete. Plus, keeping the patio low enhances your privacy when sitting in the area.
Should I do an overlay on existing concrete?
Overlays cannot fix bad concrete. At best, it can give good concrete, with minor surface wear and imperfections, a more aesthetically appealing look. Overlays are a thin application starting at 1/4 inch, so it will not be a good solution for cracks or uneven sections. If concrete is old or beat up, it’s best to remove it and lay new concrete.
What’s the grade at the edge of the patio?
Concrete should always be poured on the natural grade at the edges. Building up the edges with road base runs the risk of the new material washing out over time.
How long is the estimate good for? Our estimates expire in 30 days.
What forms of payment do you accept? Check and sometimes credit card with a 3.5% fee.
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