If you’re looking to pour your own concrete driveway, or if you are shopping around for quotes from contractors, you may be confused as to how thick your driveway needs to be. This article will discuss driveway thickness.
How thick the concrete required for a driveway is based on the weight of the vehicles that are going to be using it. Most households with cars, trucks or SUVs can suffice with a concrete slab that is four inches thick. This is based on vehicles weighing 10,000 lbs. or less. To give an example, an average SUV or pickup truck weighs between 4000 and 6000 lbs, and even a boat on a trailer generally isn’t more than 8500.
Where you will see the need for a thicker driveway is if you plan to have heavier vehicles on it. For the average household, that larger vehicle is often an RV. Most RVs start at 10,000 lbs. and go up to 30,000 (which doesn’t necessarily take into account extra weight loaded into it). So if you are looking to find a place for your personal RV, you’ll want to go up to 5 or 6 inches of thickness for your concrete driveway.
Thicker Better for Preventing Cracking?
Concrete will crack. Period. However, thicker doesn’t always mean you are getting a guarantee of less cracking. Generally, cracking is caused by other factors that can relate to thickness, but are not caused by the thickness. For example, as mentioned above, if too much weight is put on a thinner concrete driveway, yes, it can ultimately lead to cracking. Another major cause of cracking is not having a solid base beneath the driveway. Concrete does its best on solid surfaces that have no movement. In areas where the ground is mostly sand or clay, severe cracking is more likely to happen. And, in such cases, a thinner poured driveway would suffer faster than a thicker one. However, a good contractor will know how to lay a proper base to prep the land for the concrete slab, so whether the driveway is four inches or five, precautions have been taken to protect it from excessive cracking. Likewise, the use of wire mesh or rebar (reinforcing bar) in the laying of the concrete will hold the integrity of the concrete longer, regardless of the thickness of the slab.
Although pricing for the job itself has many variables and can fluctuate across the country, it is approximately 20% more concrete cost to go from a four inch thick slab to a five inch thick slab. However, adding that extra inch boosts your driveway’s weight capacity by 50%.
If you do go with the four inch thickness, you’ll save money because that thickness doesn’t require rebar to strengthen it. Most contractors use the above mentioned wire mesh that is considerably cheaper and still very affective.