Stupid or dangerous?

I've been thinking a lot lately about making my shop easier to work in, particularly things under the vehicles.

I think I've found a relatively cheap solution, so now I need smart people to tell me why it's a bad idea. 

My plan is to pickup about 6 2x12x12s and make boxes.

2 left at full length on the sides, with a third cut up and installed at the ends and one or two places in the middle, then filling the whole thing up with pea gravel. Make 2 of these boxes, and then use my steel ramps to get the truck on top of them. 

My want for this is multifold, 1) moving a floor jack on the gravel I have now SUCKS, B) I just can't afford the concrete and with the sheer volume of rain we've been getting the past couple years I'm kind of afraid of pouring a big slab, 3) while it would be semi permanent in placement, it wouldn't be hard to work around when I don't have a vehicle on it. Oh, and D), Jack stands balancing on gravel is neither fun or confidence boosting.

So, why won't this work? The gravel will compact and I'll get the truck stuck? The pressure from the weight of the truck will blow out the walls of the box and collapse on me? Buying different vehicles in the future will have different track widths and I'll be back to square one again?

I'll put the boxes together with steel brackets and lag bolts in an attempt to hold everything together. 

Why not just put 3/4' pressure treated plywood on top of the boxes?

Why not just buy more wood and ditch the pea gravel idea, make solid tire ramps out of the stacked planks. 

Ive also seen some ideas maybe even on here with interlocking blocks of wood that can be stacked for adjustable height.

In reply to failboat :

I've seen those too, but that goes back to lugging the jack around again.

I probably will lay plywood on the tops of the boxes, I'm just thinking it won't hold the weight of the truck without something inside the 2x12 boxes. 

I'm going to attempt to draw a picture, I shall return. 

Dammit, sideways. 

I want to be able to just pull in and drive up onto it, so it would need to be heavy and/or attached to the ground so it doesn't move everywhere. Hence using 3 sides and filling with gravel instead of just 4 sides

Think above ground pit. 

In reply to RevRico :

I like the idea of filling the boxes with something, but it needs something screwed across the top of all of the boxes to hold them together. If the boxes are filled tightly then plywood might work, but running another 2x12 down them & screwing it into the uprights is the easy option. 

Have you got an air compressor? An airbag Jack would be lot easier to move about on gravel and then you could use cribbing.

failboat said:

Why not just buy more wood and ditch the pea gravel idea, make solid tire ramps out of the stacked planks. 

Ive also seen some ideas maybe even on here with interlocking blocks of wood that can be stacked for adjustable height.

Stop buying expensive wood at lumber yards and big box stores. Go to sawmills. Every major city has medium size sawmills selling wood massively cheaper than the stores do.  They sell to the pallet mills, customer wood workers, railroads, but not retail.  

Except if you walk in with cash and aren’t a pest.  Know a little before you go in  like the cheapest way to buy wood is called mill run Just as it comes off the log, knots, voids warts and all.  If you start getting picky the price goes way up.  Take it as it comes. Expect  to load  and haul it home yourself. Make sure you buy enough to make it worth their time.

You can afford white oak which won’t decay anywhere near as fast as the softwoods commonly sold. Right now ash is in abundance and is a great wood. Most is nice straight grained and really strong.  But ask what they have, I got silly insane prices on left overs and odd lots.  But sorting through that takes some knowledge.  Box elder is just a soft maple but it can have really wild coloring.  Elm is a fine strong wood, it’s what framed the sides of Old Iron sides known for bouncing cannon balls off it.  Debarked it’s no danger to transporting those nasty bugs that ruined a lot of cities 

etc.

daeman said:

Have you got an air compressor? An airbag Jack would be lot easier to move about on gravel and then you could use cribbing.

 

A what now? I have a rather nice 30 gallon compressor I'd love to use more often.

You'll be asking 12' worth of lumber to hold in the pressure of the gravel and car.   You won't have a catastrophic failure and die, but over the first several uses I think you'll find the lumber bowed in the middle and the gravel settling.  Every time you drive on it, it will push out a bit and the gravel will settle in.

My ideas:  Just get a couple 2x12s.  Cut them on an angle at 36", 33", 30", 27", 24", 21", 18", 15", and 12".  Screw them together and you'll have about 14" of lift on solid ramps that can't really fail.

Another idea:  Do your original idea without the gravel and top it with 18" 2x6 pieces across.  Like a mini deck.  The deck boards will prevent the spreading of the 2x12s.  I would do three 2x12s.  You'll need one in the middle so that any car you put on it, the tires are above a 2x12.  I wouldn't suspend a car on just 2x lumber with nothing below it.

Another suggestion.... tie the two ramps together with a 2x12.  If you are just asking a vertical 2x12 to not fall over sideways, you might die a little.

In reply to RevRico :

One of These, you can also get them with long handles and wheels to make sliding them into position a lot easier.

You'd be able to use cribbing to get the vehicle up higher than the maximum jack lift. Lift the vehicle, set it down on cribbing, let the jack down, then place the jack on some cribbing and lift again.

I keep 3/4" exterior grade plywood sheets along the side of my garage. When work needs doing in the driveway which is gravel I pull them out and lie them down over the gravel.  Yeah,  still needs a jack but seriously  not a big deal. I've been increasing my jackstand collection now that we have a Harbor Freight within 30 minutes drive.  I like your idea though of being able to just pull in the driveway and onto a raised platform. One problem though. Little access from the sides. Everything has to be done through  the ends right? Could you make center sections that pull out once the vehicle is up on the platform? 

More expensive idea, but what if you just got more 2x12s and made the platforms a solid stack of 2x12 boards? Then it'd be like drive on cribbing blocks. 

In reply to vwcorvette :

Instead of dragging whole boards around I cut 1 ft squares for each jack stand,  a 2ft x 3ft piece for the jack and then an old area rug to lay on.  The rug is much nicer than laying on the plywood and easier to move and store.

Think chunky gravel if you go that route. Pea gravel will push out, while bigger chunks will brace against one another. 

Check this vid for the skinny:

https://youtu.be/xNDppVTVUss

Sounds like you are just making an above-ground pit. I too have pondered this, but was scared away by a conversation with my insurance agent. 

In reply to Nugi :

I'm thinking smaller for more density, and "integration" with the big rocks there now. On my list of things to Google when I have time is the weight of a cubic foot of sand vs gravel. 

I'd be happy just adding 2 inches of pea gravel and dust compacted across the whole floor, but between cost, delivery, and jumping jack rental I'm looking at almost as much as 7 yards of fiber reinforced concrete. 

Aside from brake lines which I refuse to do, I don't see much need for side access. I also think that adding moveable sections would turn into a massive headache. 

What makes things harder for me is I pretty much have to work alone. That means everything takes longer, and a lot of great options aren't really options because I only have two hands. 

I think that the idea behind gravel-filling it is the right direction, but the wrong approach. 

Out of safety, I'd probably either do a bunch of boards glued and screwed together with a ramp up to them. Otherwise try this, but extend it for the length of your wheelbase + 3 feet or so instead of just a wheel

The gravel is completely silly. Totally useless, and ridiculously heavy.

Build the boxes and make the top out of 23/32” Advantech  (aka 3/4”). 

I’ve done the math. 

Assuming deflection of L/180, the stuff is rated for 3339 lbs/SF when installed at 12” centers. 

Assuming your truck weighs 5000 lbs, each wheel has about 1250 lbs on it, with a footprint of about .4 SF. That’s 3125 lbs/SF. 

If you are uncomfortable with it, double up the Advantech.

Don't use plywood. Lots of reasons, but basically the laminated material does not distribute the load as well as the engineered product, and is more prone to deterioration over time. 

The gravel just adds weight, and won’t support the load (because it will settle, and spread the box sides). It will create a lateral load on your screws, which could lead to a potential future blowout. 

...but I prefer pads like the pic mtn posted. 

BTW, you are right. You need the short cross members (but not for the reason you think)

They are not needed for the weight. The Advantech can support the weight. They are needed to help prevent the sides of the boxes from laying over and collapsing the box. 

You might also want to consider pinning the boxes to the ground by driving a steel pin into the gravel. 

https://www.floorjackshop.com/the-best-car-ramps-for-convenience/

This seems related. I almost got one a couple months ago. Occasionally you see them used for fairly cheap.

https://www.kwik-lift.com/products/kwik-lift/

AWSX1686 said:

This seems related. I almost got one a couple months ago. Occasionally you see them used for fairly cheap.

https://www.kwik-lift.com/products/kwik-lift/

Not on a gravel floor, thank you. 

jharry3 said:

https://www.floorjackshop.com/the-best-car-ramps-for-convenience/

 

 

From their website:

”There have been a few reports of these ramps failing but in every case, the users were attempting to use the ramps on gravel or uneven ground. These types of ramps are designed to evenly distribute the weight of a vehicle on a hard flat surface. Something gravel definitely isn’t. When you don’t follow the manufacturer’s directions on a safety product, bad things can happen.”

SVreX said:

BTW, you are right. You need the short cross members (but not for the reason you think)

They are not needed for the weight. The Advantech can support the weight. They are needed to help prevent the sides of the boxes from laying over and collapsing the box. 

I was right then! Using 1/8"steel brackets and lag bolts, I figure more crosses means more that have to work themselves out before a problem. I was also thinking of pinning the boxes at the corners with some 1"rebar since I have it already. 

Advantech.... I never heard of that. I'll have to call the specialty yard when they open up again. 

And yea, I've looked at the kwikjacks and similar, even got excited seeing a few dirt cars on them until I see perfectly flat and smooth dirt parking spots under them. There's also the cost, the ones I've seen used are still pushing a grand. $1500 gets me a 4 inch slab. 

I wish I was still building commercially, it would be awful nice to just bring home a few chunks of beam.