It’s easy to see why homeowners select concrete driveways. Concrete is durable, low maintenance, and has a quality appearance. A variety of colors, patterns and texture give the homeowner a selection. All of these choices are useless, however if a short while after you invest in a quality driveway it becomes cracked and stained.
Pouring concrete correctly is crucial to an attractive and problem-free driveway. Here’s a few of the most important points to consider when installing concrete:
- Squeeze or compress the concrete. Concrete will only have 1/10th of its strength if it is stretched or bent instead of squeezed or compressed.
- Pour concrete on solid and compact soil. Pouring concrete over soft and un-compacted soil will result in bending and cracks on the concrete when your car drives over it.
- Install control joints in the slabs. These lines encourage the concrete to crack at these locations and not spread to other parts of the driveway. Another benefit is that these joints will help to prevent cracks by allowing concrete to expand or contract as it does during different temperatures. Without these joints, expansion or contraction that is repeated usually results in cracks. Installers need to make sure the controls are deep enough. Control joints should be ¼th the thickness of the slab and they also need to be spaced properly. This means spacing them at intervals of 15 feet or less.
Homeowners have options when it comes to sizes and material choices for their concrete driveway. Whether 4 inches thickness is enough, what steel does for the driveway and should it be used as well as what to look for in concrete are all commonly asked questions.
Sizes and Materials to Choose
- Concrete should be at least 5 inches thick. Thicker concrete is better for driveways and the cost between 4 inches and 5 inches is not a lot when considering the total cost of the job.
- Use reinforcing steel. Steel is inexpensive, helps to strengthen the concrete and will hold cracked slabs together. It’s often easy to tell when steel isn’t used because cracks can grow in size and two adjacent pieces of slab can be two different heights. To take advantage of steel’s effectiveness, it needs to be placed less than two inches down from the top of the slab.
- Concrete contains cement, water and aggregate (sand or rock). The more cement and the less aggregate concrete contains, the stronger the concrete is. The standard for concrete is a 4,000 psi (pounds per square inch) strength rating. Ordering concrete that is 4,500 or 5,000 psi will cost more but more cement is added per cubic yard. If you expect that the concrete will be subjected to rough conditions, the higher psi could be a worthy investment, adding an extra 25 to 50 years to the life of the cement.
How to Preserve Your Driveway
- Most driveways are connected to a lawn. A way to prevent grass from growing up through your driveway is to remove the sod within 2 to 3 inches of the cement. Water and rain will drain off the surface better as well.
- Trees, bushes and other plants can cause problems if they are growing too close to your driveway. Roots will grow up through the cement, cracking it and causing it to break off and crumble. Moving these plants if they are not too big will solve this problem.
- The simplest thing you can do to keep your driveway looking nice is to clean it off occasionally. Use a leaf blower to remove leaves, grass, sticks and other debris. Using a pressure washer to spray clean the area immediately after spilling oil, gasoline, grease or other stains is the best bet for removing these types of stains.
- Try to keep heavy trucks and equipment off your driveway because although concrete is durable, it’s not meant to hold heavy vehicles and large equipment.
What to Do in Inclement Weather
- Keep water and rain that runs out of the gutters from running onto your driveway. This is important because if water gets under your driveway during the freezing winter months, it can rise up and crack your driveway.
- Use care when plowing or shoveling your driveway. Lift the blade up so not to scrape or crack the driveway.
- Avoid putting salt on your driveway. Salt can cause scaling, crumbling and cracks on driveways. Using salt during the first winter your driveway has been poured is especially harmful. Consider using an ice melter instead, which will turn snow and ice into water without damaging the cement.
When to Seal Concrete Concrete that meets certain criteria does not need to be sealed. Most likely your driveway does not need to be sealed if the concrete:
- Has enough cement (6 bag mix or 564 lbs. of cement) AND
- And has 4,000 lbs. per square inch design strength AND
- Includes just enough mix water to give it a 4 inch slump consistency AND
- Is finished without water AND
- Is moist cured with a liquid curing compound or with plastic
However, if concrete is poured poorly, it should be sealed. Do not seal with film-forming silicone. Instead use siloxane water repellants or high quality silane. Using a quality product will let you get a way with only sealing your driveway every two to three years. Be sure to read and follow the directions on the container for the best results.
Follow the above advice and your concrete driveway will hold up against cold weather, ice and salt, vehicle traffic, basketball games and bike riding for years. Many driveways can last over 30 years without major repairs.