What You Need To Know When Designing And Building A Concrete Driveway
Before installing a concrete driveway there are plenty of questions to consider regarding aesthetics, quality and overall durability. A concrete driveway should last you many years without it having to be replaced, despite the fact big vehicles weighing thousands of pounds drive and park on it day after day.
When concrete installation is properly designed and implemented, the results can be fantastic, and incredibly durable. On the other hand, poorly or improperly laid concrete can lead to issues—especially unattractive surface cracks. If you are considering installing a concrete driveway here are some of the most important things to consider, question, and plan for.
Concrete Vs. Asphalt
When putting in a new driveway you may be faced with deciding between concrete and asphalt. Concrete driveways can last 30-years or so without needing any maintenance work, while asphalt requires regular touch-ups here and there. Age-related cracks are very common in asphalt and therefore asphalt requires applying constant coats of sealants. Even when asphalt is well maintained and properly installed it is more prone to wear and tear from vehicles driving over it, and weather exposures. Once you consider all of the costs associated with maintaining and replacing asphalt concrete ends up costing much less.
What Type Of Concrete Should You Use For Driveways?
Driveway concrete should be at least 4,000 PSI and contain 6% air-entrainment. A moisture-reduction admixture will help reduce the amount of water to cement ratio. In general, high-performance concrete mixes have additives such as fly ash in order to improve workability of the concrete without having to add additional water—which is convenient because adding too much water during installation can lead to a higher likelihood of cracks. There are other concrete mixes that might be cheaper but they are going to be harder to work with and may cause problems.
Concrete Thickness Counts
The weight and strength of a concrete driveway has so much to do with the thickness of the concrete. It is recommended that concrete driveways are no thinner than 4-inches. Installing a concrete driveway that is 5-inches as opposed to 4-inches will cost approximately 20% more, but this 1-inch difference will add 50% to the overall load-carrying capacity of your driveway.
How To Avoid Cracks in Concrete
For the most part, minor concrete cracks do not cause any real damage and will not reduce the overall lifespan of the surface, although cracks do create an eyesore. Many different things can cause concrete to crack, although there are some tactics you can implement to help prevent cracks from occurring in the future. Interestingly, the majority of concrete cracks are caused by improper design and installation. As concrete solidifies it is always going to shrink a little, this is where many problems arise because joints are not properly spaced to accommodate for this.
Other leading causes of concrete cracks include:
- Isolation and control joints are omitted
- Jointing is not properly conducted
- Incorrect preparation of surfaces and materials
- Too much moisture, either in concrete or at job site in general
- Improper curing, or no curing at all
- Use of inefficient concrete finish
The Point Of Curing Concrete
Curing is a very important element to long lasting concrete; concrete that is not properly cured is 50% less durable. The curing process involves keeping the surface moist in order to help prevent weather damage and future defects.
Concrete Joint Patterns
Picking joint patterns for concrete can be more difficult than often assumed. It is so important that the proper patterns are picked; some joint patterns are known to increase the risk for cracks in concrete. For instance, joints that are spaced too far apart lead to random cracking. In general control joints should never be spaced more than 10 X 10 apart. If a particular joint pattern creates a rectangular or triangular shape, concrete is also more likely to crack. Joints should be planned out so that they create square, uniform sections, and it is better to have smaller sections as opposed to larger.
Concrete Finishes & Seals
The 2 most popular concrete finishes include hard-troweled and broom finish. Trowel finish is most popular for indoor concrete where the surface is flat and smooth. A broom finish is often used for driveways and sidewalks because it offers more durability and a slip-resistant surface. There are also decorative finishes to choose from including colored, exposed aggregate, and patterned.
It is also important to seal your finished driveway in order to help prevent the absorption of water and chemicals. Using the proper concrete sealant will prevent your driveway from obtaining surface defects as well as reduce stains and improve ease associated with cleaning up spills.
At Turnbull Masonry we provide the highest quality concrete installation, repairs, and maintenance. Call us today to see how we can benefit your next project!