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If you’re looking to pour your own concrete driveway, or looking for quotes from contractors, you may not know how thick your driveway needs to be. This article will discuss the thickness of the driveway.
Weight
The concrete thickness required for a driveway is based on the weight of the vehicles that will use it. Most homes with cars, trucks, or sport utility vehicles can suffice with a four-inch-thick concrete slab. This is based on vehicles weighing 10,000 lbs. or less. To give an example, an average SUV or truck weighs between 4,000 and 6,000 pounds, and even a boat on a trailer usually weighs no more than 8,500.
Where you will see the need for a thicker driveway is if you plan to have heavy vehicles on it. For the average household, that largest vehicle is usually an RV. Most RVs start at 10,000 lbs. and go up to 30,000 (which doesn’t necessarily take into account the extra weight carried). So if you’re looking for a spot for your personal RV, you’ll want to be up to 5 or 6 inches thick for your concrete driveway.
Is thicker better to prevent cracks?
The concrete will crack. Period. However, thicker doesn’t always mean you’ll get a guarantee of fewer cracks. Generally, cracking is caused by other factors that may be related to thickness, but are not caused for the thickness. For example, as mentioned above, if you put too much weight on a thinner concrete driveway, yes, it can ultimately lead to cracking. Another major cause of cracks is not having a solid foundation under your driveway. Concrete works best on solid surfaces that are not moving. In areas where the soil is mostly sand or clay, severe cracking is more likely to occur. 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 foundation to prepare the ground for the concrete slab, so whether the driveway is four inches or five inches, precautions have been taken to protect it from excessive cracking. Also, the use of wire mesh or rod (rebar) in concrete placement will maintain the integrity of the concrete longer, regardless of the thickness of the slab.
price differences
Although the price of the job itself has many variables and can fluctuate across the country, it is about 20% more expensive on concrete to go from a four inch thick slab to a five inch thick slab. However, adding that extra inch increases the weight capacity of your entry by 50%.
If you choose the four-inch thickness, you’ll save money because that thickness doesn’t require rebar to strengthen it. Most contractors use the aforementioned wire mesh, which is considerably cheaper and is still very effective.