Low car, steep driveway

[bran_solo]

Hey folks, I'm in the process of building a 2 car garage at my house and have been following a ton of threads here for ideas/inspiration. Some very cool stuff happening here.

Our place is challenging with lots of hills and not a lot of choice for placement. The short version is that the final approach to the garage will be up a hill, about a 20-22% grade, and it occurred to me that the sharp angle between the pitched driveway and the level garage floor is at risk of scraping or high-centering a low car. I once owned a really low car that would sometimes get stuck on steep parking garage ramps, and I really don't want to repeat that (on a daily basis).

Getting down the driveway will actually be fine - the grade evens out and the transition to the road isn't the sharp angle that causes most bumper scrapes on low cars.

Has anyone encountered this, and if so do you have any wisdom on how I might fix it? Or let me know if I'm overthinking it.

I know very little about driveway grading. The only idea I had was to get one of those rubber curb ramps (https://www.bridjit.com/) and place it inside the garage so the front wheels get lifted up at just the right spot to get the middle of the car over the crest.

 

[P0234]

It certainly can be an issue depending on how the transitions are between the grades. If you Google Corvette and approach angle you will find a bunch of posts dealing with the subject. I think anything over 11% will cause scraping. These guys have a handy calculator:

Angle of Approach Calculator

Use the calculator below to determine your vehicle’s maximum angle of approach. Then shop for any ramp with an angle equal to or less than your result.

www.raceramps.com

 

[mike93lx]

20% grade is really steep. I think you need to revisit the location or elevation. Maybe dig it down and retain the soil around it with foundation walls

You'd never be able to push something in or out of your shop, either

 

[johninct]

20% grade is really steep. I think you need to revisit the location or elevation. Maybe dig it down and retain the soil around it with foundation walls

You'd never be able to push something in or out of your shop, either

Stuff will be able to be pushed out , but it is not going to stop. My cousin was detailing his car on his steep driveway in neutral. It ended up across the street hitting the neighbor's house.

 

[Stuart in MN]

You can improve your odds by how you contour the driveway - instead of it making a straight line from the edge of the street to the edge of the garage floor, look at how ramps for loading motorcycles into pickups are built. They have a slight arch in the middle that helps to minimize bottoming out.

 

[racecougar]

If there is room to curve the driveway or throw a switch back into it (no idea if this is on acreage or in a subdivision) to improve the grade, I'd sure suggest it. If not, arch it to avoid a sharp angle change as Stuart suggests above.

 

[Rusted Nut]

As others have said, make the driveway longer, contour it, and lessen the grade. Also check local reps, as 16% is code max in some areas.

 

[CoogarXR]

I don't know what the weather is like in your area, but if ice is common, consider that too.

My driveway isn't near that steep and my work van that gets parked on the driveway slides down on the ice (in park, unattended) several times a season lol.

 

[mike93lx]

Stuff will be able to be pushed out , but it is not going to stop. My cousin was detailing his car on his steep driveway in neutral. It ended up across the street hitting the neighbor's house.

Lol. Touché

 

[Fav Onefour]

I have a steep drive and attached garage. Our whole side of the road has homes with the same issue. North facing in a cold climate. It's a lot of work. The houses shade most of the driveways during winter so there's no ignoring snow and ice.
Some of the homes have a steep door pad/approach. I had that setup initially. It is more work. That is the most heavily used section of the driveway. Every little project needed to be done in the garage because the pad was so steep.
Even without the ice and snow issue, the drive is hard to use. Doors on vehicles won't even stay open. People with mobility issues need help just getting in and out of vehicles. It's hard to use the drive for loading and unloading.

I redid the grade and went with heated drive. It's not a cheap option.
If I had a chance to rebuild, I'd lower the garage.

In this situation, it sounds like there is room to revisit the grade approach and maybe garage floor elevation. I'd consider both.

 

[dcg9381]

We'd need to see the lot / survey. If you can "sweep" that approach perpendicular to the slope, that gives you the ability to bring a low car at an angle and gradually increase the approach once all 4 tires are on the drive.

We don't have ice issues here, but it'd be a concern elsewhere.

 

[P0234]

I have a steep drive and attached garage. Our whole side of the road has homes with the same issue. North facing in a cold climate. It's a lot of work. The houses shade most of the driveways during winter so there's no ignoring snow and ice.
Some of the homes have a steep door pad/approach. I had that setup initially. It is more work. That is the most heavily used section of the driveway. Every little project needed to be done in the garage because the pad was so steep.
Even without the ice and snow issue, the drive is hard to use. Doors on vehicles won't even stay open. People with mobility issues need help just getting in and out of vehicles. It's hard to use the drive for loading and unloading.

I redid the grade and went with heated drive. It's not a cheap option.
If I had a chance to rebuild, I'd lower the garage.

In this situation, it sounds like there is room to revisit the grade approach and maybe garage floor elevation. I'd consider both.

You bring up some really good points. We had a neighbor a long time ago that had a 15 or maybe 20% driveway and it was unusable for any sort of parking. Even driving up it, you were looking at the sky, made it interesting pulling into the garage.

 

[bran_solo]

Thanks everyone for all the input.

I spent some time measuring my driveway today and I'm quite certain the surveyor made some mistake in his measurements, I'm measuring a <15% grade. I'm no expert, but the area I measured had a 58" elevation gain over 438", that's 13.2% grade right?

 

[jshillin]

As long as it's not too steep to overcome, a lowered car can get into most driveways if you go in at an angle. My driveway is steep and 2 of my vehicles are low, I have to come in at a hard angle so my passenger side rear wheels goes into the driveway and it's almost like I'm back across it instead of into it, then once my front bumper is up into the driveway, I start cutting the wheel back and I'm fine. I've had a lot of lower vehicles over the years, so it's just second nature to me.

 

[Fav Onefour]

Thanks everyone for all the input.

I spent some time measuring my driveway today and I'm quite certain the surveyor made some mistake in his measurements, I'm measuring a <15% grade. I'm no expert, but the area I measured had a 58" elevation gain over 438", that's 13.2% grade right?

That won't be too bad. Biggest issue is the length if you want to try for leveling out a section.
I honestly do like having the flatter area next to the garage for usage.
BTW, I use the same angle trick @jshillin describes. If I hit the drive straight, it's drag city. Use the angle approach and it might lift a wheel but it's not dragging bumpers.