FAQs


General Questions About Concrete

Do-It-Yourself Questions

Other Residential Concrete Application Questions

What is concrete?  Is it the same thing as cement?

Concrete is a composite material that consists essentially of a binding medium such as cement (commonly Portland cement) within which are embedded particles or fragments of aggregate. Concrete solidifies and hardens after mixing with water and placement due to a chemical process known as hydration. The water reacts with the cement, which bonds the other components together, eventually creating a stone-like material. Concrete is used to make pavements, architectural structures, foundations, motorways/roads, bridges/overpasses, parking structures, brick/block walls and footings for gates, fences and poles.

Cement is a substance made by burning clay and lime.  In essence, then, it is a mixture of silicates and aluminates of calcium.  It is mixed with water to make mortar, and mixed with sand, gravel and water to make concrete.  People frequently use the term “cement” when they are referring to “concrete”, for example, by saying, “Our house has cement floors.”

 

Are there different kinds of concrete?

Yes. Concrete can be made to order in terms of strength, workability, and durability. For more information, call 1-800-CEMSTONE or 651-688-9292.

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What is the process of curing and sealing concrete?

Curing concrete is a process used to help retain moisture in the concrete to facilitate proper strength gain. Concrete should be cured immediately after the final finishing has been completed. To cure concrete water must be used to hydrate the cement. The best way to do this is to water concrete continuously.

Sealing concrete is done at least 30 days after the concrete has been placed. This process provides a barrier to prevent water and other chemicals from penetrating the concrete. Sealing is critical to exterior concrete to ensure durability and resistance to freeze-thaw cycles. Concrete should be sealed every 2-3 years.

Application of curing and sealing products is best done with a low-pressure sprayer. If that is not available, a fine-napped paint roller may be used, however, achieving uniform coverage is more difficult with this approach.

Cemstone recommends two methods to cure and seal concrete:

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Is the process of installing concrete affected by weather?

Yes. The rate at which concrete hardens is very much affected by temperature, moisture and wind.  Wind can cause the surface to crack.  Rain will significantly weaken the surface. That's why it's important to work with the right concrete mix for your application.

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Is there a recommended on-going maintenance program?

In addition to sealing concrete every 2-3 years, do not allow rusting metals to set on the concrete. For information about removing stains from concrete, call Cemstone Contractor Supply at 651-905-1500.

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What steps do I need to remove a stain from my concrete?

Light Duty Concrete Cleaner is a general purpose construction stain remover that is formulated to dissolve mortar smears, mud, oil, rust, dirt, and more on smooth concrete and most brick and natural stone.  It will not etch or alter surface texture and is safe for most pigmented concrete and colored mortar. It contains no muriatic acid.  For more information, call 651-905-1500.

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Will concrete crack?

Concrete will often crack especially in freeze/thaw climates.  To minimize and control cracking, control joints or “cuts” are placed in the concrete so that the concrete cracks where those control joints are placed.

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Does the presence of cracks indicate a structural problem?

In most instances, the answer is no. Very narrow "hairline" cracks are superficial and do not indicate any structural problem. Cracks that have movement where one side of the crack moves relative to the opposite side should be evaluated by a professional engineer.

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Why do concrete surfaces sometimes flake or spall (break into fragments)?

Concrete surfaces can flake or spall for one or more of the following reasons:

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Is there anything that can be done to help control cracking and spalling?

Caulking your control joints will help distribute tire loads across the joint and prevent spalling. It will also keep debris out of the joint that can cause cracking when the concrete expands. Call 651-905-1500 for more information and product recommendations.

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Why should I choose concrete over asphalt when asphalt is less expensive?

Consider the cost of the driveway over its lifetime. A good quality concrete driveway will last more than 30 years with little maintenance. Asphalt driveways need regular periodic sealing coats to retard age-related cracking.  Deterioration of even properly constructed residential asphalt driveways will occur more quickly due to environmental influences than due to vehicle traffic. If you factor in the cost of surface and crack sealers and the shorter life-span of the asphalt, concrete will cost much less over the life of the structure. Furthermore, the concrete structure will not harden in sunlight, resulting in a more consistent surface over time.

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How do I determine how much concrete I'll need?

Click here to see our easy-to-use Concrete Calculator to determine how much concrete you'll need for your project. And if you need to speak to someone about delivery information, click here.

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What’s the difference between concrete that Cemstone delivers and the bagged mixes I can buy at a home center?

The main difference between the two is Cemstone's quality and consistency, and the fact that Cemtone’s ready-mixed concrete is made just for your application so its properties can be altered, as needed, up to 1 hour before it’s on your project site.

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What should I know about working with concrete? What precautions should I take?

FRESHLY MIXED CEMENT, MORTAR, CONCRETE OR GROUT MAY CAUSE SKIN INJURY.  AVOID CONTACT WHERE POSSIBLE AND WASH EXPOSED SKIN AREAS PROMPTLY WITH WATER.  IF ANY CEMENT MIXTURES GET INTO EYES, RINSE IMMEDIATELY AND REPEATEDLY WITH WATER AND GET PROMPT MEDICAL ATTENTION.

Click here to learn more.

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What kind of tools will I need to pour and finish concrete?

Cemstone Contractor Supply is the upper Midwest's premium source of concrete and masonry products with more than 10,000 high quality and high performing products available. We can even rent you the tools you'll need. Click here.

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What if I need concrete delivered to the back of my house, or someplace that’s located away from the driveway or street?

Cemstone features a full line of the latest Schwing pumping equipment and Theam conveyors to place concrete in hard to reach locations. We can also schedule the pump and concrete to arrive at your job so you don't have to juggle two suppliers. We call that Blue on Blue Service. For more information on our concrete placing capabilities click here.

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What if I don’t want grey concrete?

Color it! You can get an idea of the possibilities by linking to our page on decorative concrete.

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Can I get caulking that’s colored to match my existing or colored concrete?

Yes.  Cemstone carries a line of Tremco Caulking Products that come in a variety of colors to match your concrete.

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What if I want to change the color of my existing driveway/concrete?

There are many ways you can color existing concrete, including acid staining, water based stains and tinted sealers.  Lithochrome Chemstain Classic acid stain is a reactive penetrating stain developed exclusively on new or existing concrete surfaces and cementitious toppings.  Chemstain Classic produces variegated, translucent color effects unique to each surface.  The beautiful patina is ideal to simulate the shadings of natural stone or create artistic faux finishes.  Due to their chemical reaction with concrete, Chemstain colors become part of the surface.  They will not fade, chip, crack, or peel.  Initial application of a compatible sealer or coating and periodic maintenance are required.  Lithochrome Tintura Stain is an environmentally friendly, penetrating water based formula specifically designed to stain concrete or cementitious  toppings.  Developed for interior use, Tintura Stain can be color matched to the full range of Scofield colors.  Cemstone’s CPC Tint Paste can be added directly to our CPC Cure & Seal and applied directly to your existing concrete.   CPC Tint Paste comes in wide range of colors.

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Can a homeowner seal their own concrete or should that be left to a professional?

Homeowners can certainly seal their own concrete but it’s recommended they speak to a knowledgeable representative at Cemstone to ensure the right products are used and applied correctly. Call 651-905-1500 for expert advice and quality products.

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What should I do when bonding new concrete against existing concrete?

The existing concrete should be roughened.  Any grease, debris, laitance and other materials which may inhibit bond must be removed. The existing concrete is then soaked for at least 24 hours. Immediately prior to placing the fresh concrete, blow any standing water away and scrub a bonding layer of mortar to the surface. The bonding mortar should consist of cement and sand (1:3 in volume) with the consistency of heavy coffee cream. The mortar should not be allowed to dry prior to placement of the new concrete.  If you are abutting to an existing structure, it is necessary to use isolation.

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What are ICFs?

 

ICF stands for Insulated Concrete Form. With ICFs, you can create buildings that are energy efficient, environmentally friendly, quiet and comfortable. With ICFs, the goal is to produce a builiding envelope that more effectively resists harmful mold, dust, and allergens and withstands powerful wind, storm and fire threats when compared to conventional building methods.  Additional benefits are low maintenance and greater design flexibility.  The interest in residential homes built with ICFs for above grade walls is rapidly increasing.

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Where can I find information on ICFs?

For more information, click here.

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Where can I find more information on Decorative Concrete?

For more information, click here.

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Will Cemstone finish the concrete for me?

No, but we can recommend a contractor.  Cemstone makes materials for many qualified contractors to install. You can click here for a list of professional concrete contractors who are experts for residential concrete applications.

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How much can I expect to pay for a new concrete driveway?

The cost can range anywhere between $4 to $10 per square foot.

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