What Is the Maximum Driveway Slope (or Grade)?

If you live on a hill, then you may be wondering just how steep your driveway can be before it becomes a problem. But knowing the maximum driveway slope or grade you can have gets a little confusing depending on where you live, local regulations, climate, and more. Let's break down the maximum driveway slope once and for all.

What Is a Driveway Slope?

A driveway slope is the percentage that your driveway rises over 100 feet of pavement. For example, if you have a 10-foot rise in elevation per 100 feet, that’s a 10% slope. Your driveway should gradually rise as it goes toward the house, with your home sitting at the highest point. 

Why Does My Driveway’s Slope Matter?

A driveway slope helps prevent rainwater from collecting around the perimeters of your property during a storm. If you have a negative slope, this can cause structural, foundational, or interior damage to your home. 

In some climates, having too steep of a driveway slope can cause your vehicle to slip and slide down the driveway in freezing or rainy weather. That's why most municipalities have their own guidelines to ensure homeowners take safety into consideration. Every region is different, so what applies to one city may not apply to another location.

Maximum Driveway Slope 

The maximum driveway slow is 25%, but most places don’t allow for anything over 20%. Generally speaking, a maximum slope for residential driveways is location-dependent and falls somewhere between 10% and 18%, with 15% or higher considered to be a very steep slope.

Factors that Affect the Maximum Driveway Slope

While it's important to check with your local and state regulations when it comes to your driveway’s maximum slope, you'll still want to be aware of factors that could impact the safety of the driveway's gradient beyond general standards. Here are some of the biggest driving factors:

Driveway Material Type

The type of driveway material you have could impact how well your driveway handles a steeper slope. Surface traction can make the same slope on a sunny, dry day a completely different story after rain or ice. If your area allows for driveways with a slope of 15%, this may be the maximum slope for permeable pavements—not for driveways with impermeable pavements like concrete.

Location 

Where you live can mean all the difference between a steep driveway and one that needs local grading services before you can lay pavement. If you don't have a long driveway, then a steep driveway slope may not be possible. There needs to be enough space toward the bottom of the driveway for cars and trucks to exit without damaging the bottom of the vehicles.

Climate

Some regions are stricter than others when it comes to driveway slopes. Areas that experience icy weather or frequent storms may have a lower maximum driveway slope to help protect residents from losing traction, whereas arid and mild climate zones may have more wiggle room for steeper driveways.

Tips on How to Fix a Steep Driveway Slope

Safety is the most important factor when it comes to having the right driveway slope. Here are some tips on how to fix your driveway slope for a safer driveway:

• Use permeable pavers instead of impermeable pavement for added traction.

• Install a ramp at the end of your driveway to avoid undercarriage damage. 

• Hire a driveway paving company near you to pour resin on the surface of your driveway for extra grip.

• Put speed bumps on your driveway to reduce slipping.

• Regrade your driveway. The cost to repave a driveway is around $6,800 on average.