Concrete curb/footer to support metal carport

[Eos]

Is this possible?

I was leaving her house today, my friend mentioned to me that she wants to add a carport to her asphalt driveway, except there is a slight incline to it and everything I've read this evening is that the installation area for a carport needs to be flat. The grade looks to be maybe 8" over 20'. It was dark so I couldn't measure.

My idea would be:

1. saw cut and remove the asphalt down to the underlayment (hopefully gravel) just over 6" wide in two strips that match the width of the carport
2. setup forms that are *just inside* the saw cut
3. drive vertical rebar into the underlayment, staying below the eventual concrete height (unsure about this process)
4. tie horizontal rebar to the verts
5. pour the concrete, maybe placing j-bolts in the wet mud at the exact positions to secure the bottom carport mounting rails
6. let concrete setup, remove forms (maybe cold patch in the empty areas where the forms were?)
7. attach mounting rails to concrete and construct carport

See the image for the side view of the basic idea. The line underneath is the asphalt driveway. The wedge is the proposed curb/footer. Top view is simply two pairs of parallel lines, with a large gap between the two inside lines. 😉

Is this possible, or would another solution help get some weather cover for her car?

 

[Greenman]

Is the carport to be a wood framed structure or a light weight free standing one?

 

[Eos]

Is the carport to be a wood framed structure or a light weight free standing one?

Metal framed.

 

[Greenman]

Your plan will work. Don't drive rebar into the dirt though, hang it from the forms with tie wire. All the steel should be 2" from dirt. You probably don't need any vertical bars at all.
Depending on the size of the building you may need an actual footing in the ground. Wind load can be substantial, an 8x20 wall (side of a garage) will be under 1800 pounds of load in a 50mph wind. You'll pick up a bit more depending on roof pitch.

 

[Eos]

Thanks for the reply. I appreciate it.

 

[deadlyapp]

If you're going through this much work - why wouldn't you just make a custom four post carport? Wouldn't matter if there was a slope - you'd just have taller beams on one side than the other and set your minimum height to the vehicle based on the high side.

 

[Greenman]

Those are really hard to stabilize without the posts sunk in the ground, a system that will always fail. I rebuilt 192 that were done that way.

 

[deadlyapp]

Those are really hard to stabilize without the posts sunk in the ground, a system that will always fail. I rebuilt 192 that were done that way.

Oh I 100% agree he would still need to pour concrete feet for it, but no need to pour an entire length of level surface I guess was my mindset.

 

[Red Squirrel]

Just be careful you don't get into anything that requires permits then it ends up being a big and expensive job with lot of red tape and your taxes could go up, all for a silly shelter.

Most people here just tie cinder blocks to it and lay it on the driveway without any permanent support. With the cinder blocks and once you start to get decent snow accumulation around it, it's not going anywhere. At least, usualy. Sometimes they do fly away in big storms. City started to crack down on that though and they still require permits now though... Was going to get one but never ended up doing it, and no point now. There's a way around it, and it's to declare it as a greenhouse and just have hanging plants you can park under, but you better have a green thumb because they will check on your plants.

 

[Icemdave]

I’d pour a shallow concrete curb on the high side and a deeper one on the low side so the posts land level without fighting the driveway slope. A buddy of mine ran into something similar while getting gutter installation and cleaning in Dallas TX and the crew there pointed out how small grade fixes like that make the whole structure sit tighter. Keeps the posts from twisting over time.

 

[Greenman]

I’d pour small level pads at each post location rather than a full curb. It keeps the posts plumb, works fine on a slope, and costs a lot less.

Been 3 years, my guess is there is just a bit of paint work left to finish.