FAQs Frequently Asked Questions
Concrete is a mixture that is made up of 5 ingredients:
2. Coarse Aggregate (pre-washed premium 19mm blended stone)
3. Fine Aggregate (pre-washed premium concrete sand)
5. Chemical Admixtures (mainly used for enhancement purposes)
The strength, flexibility and resistance of the concrete depends on the mix of ingredients used and the water-cement ratio. The best mixtures will be custom based on your soil and climate conditions.
Using our handy concrete calculators on our Tools Page can help you determine how much concrete your project will need so that you can properly budget your project. However, the calculators are only approximations of the concrete your project may require as the reality of your soil, weather conditions and project needs will also factor in to the finished needs.
The following can also be used as a good guideline:
• If concrete will be exposed to freeze/thaw cycles, then an air content is needed
• A minimum curing period of 7 days will gain 70% of the full cure strength
• At 28 days of curing the concrete will be at 100% of its strength and will slightly gain more strength after.
• Freshly poured concrete that is not protected or cured properly could lose a considerable amount of its strength.
Choosing the best concrete will depend entirely on the kind of project you have in mind. Exterior concrete applications will require “air-entrainment” for tougher, more resilient yet flexible mixes in order to stand up to the harsh freeze thawing weather conditions experienced by Canadian cities. Indoor concrete applications will require a mix that can be better moulded and offers a higher degree of finishing options.
Curing is the process of hardening after the concrete is placed. Curing is what will determine the eventual strength and durability of the placement. It is crucial for concrete to remain moist during the curing process and it must also be maintained within a favourable temperature range. The curing process generally takes 7 days and for that time the concrete must be kept moist; this can be done using soaking hoses, sprinklers or by covering the concrete with wet burlap. You can also purchase commercial curing compounds that can be sprayed on the concrete in order to seal in the moisture.
Absolutely. Any temperature extreme can adversely affect your concrete placement. Make sure that your contractor is prepared to make adjustments to account for cold or hot weather conditions.
Concrete is very porous. It absorbs liquid in small quantities and this liquid can damage concrete in different ways. If a solvent is dropped on it, the concrete will be slowly eaten away. On the surface you will see pitting – something that is easily repaired, but underneath is where the permanent damage will occur. Water is another concern. Water will go into the microscopic holes in your concrete, then if it freezes, the water will push against the concrete creating microscopic cracks, which will eventually spread causing the concrete to weaken. Sealing your concrete project will protect it from damage – not only from water and solvents, but also from the damage that can be caused by dropping heavy objects on it and the wear-and-tear of every-day use. Sealing your concrete will increase its strength and longevity for years to come.
The kind of sealer you should use is really dependent on the kind of concrete used for your placement. However, in general: Exposed Aggregate: Should be sealed with a high gloss sealant that gives it a “Wet Look.” Sealing is important in order to protect the concrete from the water and contaminates that would otherwise be absorbed by the porous surface. Unsealed, the concrete would suffer damage from freeze/thaw cycles and also be more susceptible to staining. Stamped Concrete: Should be treated with a liquid repellent in order to give it added protection against spills and stains. Care should always be exercised when using a power washer on concrete surfaces as it can seriously damage the top layers. Garage floors: Epoxy sealers are best for garage floors since they are nearly impervious to battery acids, oils, salts and all other chemicals; they are easy to apply and can be purchased in a number of colours. There are a number of different sealers for different applications. Among some of the best are those that contain silanes and siloxanes since these products partially fill the concrete matrix thereby preventing the absorption of water and/or contaminants.
Caring for your concrete is crucial to prolonging the life of your project. Taking proper care of concrete in the winter is especially important as the harsh Canadian climate can quickly damage even the toughest concrete pour. Here are a few guidelines to keep in mind. A. Do NOT use De-icers during the first year. Concrete takes a long time to cure and to reach its maximum strength. Although salt will not react with concrete it does increase the number of thaw/freeze cycles that the concrete must endure and can damage the concrete before it has reached its peak strength. B. Use sand during cold weather – or anytime. Your best option when it comes to making concrete skid resistant is ordinary sand. Sand can easily be purchased from any hardware supply store. C. Avoid De-Icers containing Ammonium Nitrate or Ammonium Sulfate. Some of the most commonly sold and used de-icers available contain these harmful chemicals, which will quickly disintegrate your concrete. D. SEAL your concrete. Once your concrete has been finished you have to seal it in order to ensure optimum protection. After the first winter then you can begin using icemelters.
Keeping your concrete free of snow, ice, slush and water is paramount to ensuring that your concrete comes through the winter months without damage. By clearing it of all snow and ice, you are actually limiting the amount of water it is exposed to during freeze/thaw cycles. Another good tip is to use a plastic shovel instead of metal one since metal can inadvertently chip the surface.
Salt is actually quite corrosive and in the long-term will cause your concrete to degrade. So, it is best to use commercially prepared icemelters that do not contain harsh chemicals.
The short answer: NO. Since all icemelters contain salt, they cannot be considered good for the environment. However, there are some brands that are less harmful for the environment than others. Your best bet is to look for brands that are marked “Pet Friendly” instead of “eco-friendly.” However, to really be environmentally conscious then you would stay away from icemelters altogether and instead use traction aids such as sand, gravel, kitty litter or sawdust.
Concrete cracks because it shrinks imperceptibly when it dries – that is why contractors place joints in concrete, to ensure that it cracks neatly.
When concrete is exposed to repeated freeze/thaw cycles it can sustain damage. When water is absorbed by the concrete and then freezes, it exerts pressure. When the concrete can no longer hold the pressure it releases it through scaling, flaking or pitting.
Fresh stains are always easier to remove than old stains. When something spills on your concrete, try to blot it immediately with a rag. Get out as much as you can then scrub at it with a nylon brush using dishwashing soap and water. Let the soapy solution soak into the stain before scrubbing at it. Each time you scrub, blot the surface with a clean rag and start over until the stain is gone. However, if the stain has set you will most likely have to use a commercially prepared stain remover. Make sure that the remover is meant for concrete and for the kind of stain you are dealing with. Sandblasting and other dry remove methods are not very recommended since they can easily damage the surface of your concrete placement.