I spend a decent amount of time under vehicles, including spraying undercoating, which can add up to hours of rolling around under there. So I was invested in finding a better solution to gain a little more height than was afforded by regular jack stands, and to improve strength and stability. Cribbing made from lumber is a time-tested method to get a strong and stable support under vehicles. Looking at a number of common layouts, I set out to make a more efficient, compact, and stronger rendition of the idea.*
Each block has a 16 by 10 inch footprint, and lifts 6 inches high to the deck. Raised cleats chock the tire on the top block, and serve as the interlock between stacked blocks. The notch underneath part A is a handhold that I added after the first set, to make for easier pickup and carrying with one hand.
Full-height ribs transfer weight through solid wood all the way to the floor.
To build it, I flattened all the board faces on the jointer for tight fit and glued faces - they were all just scrap common 2×6 lumber. Glued everything that touches. Framing nailer to pop it together, and then some construction screws to finish assembly. I pilot drilled the cleat end pieces for screws to help prevent cracking as they take some pressure from tires.
Loading onto a 12 inch double-stack usually takes two bites with my jack - first lift onto 6″ block, then add the jack post extension and lift up to add the 2nd block for 12″. (On most jack points, rear axles/diffs, I can’t fit the jack under there with the extension up.) The 12″ double-stack has worked great coming on 2 years, rock solid, no indication of wear or damage.
I’m thinking I’ll build another pair and try 18 inches with a 3-stack at some point (I’ll need to work out my jacking solution to make sure I can get tires to clear up that high, though. My Badlands offroad jack has a pin adjustment on the pad extension, will have to test max height on that)
If I was starting over and planning for triple-stacking, I might go a little wider just for the wider footprint stability. Wouldn’t be hard to make a wider block backwards-compatible - keep the cleat the same 7″ width and then just put new wider blocks on the bottom and stack up from there.
As it is, the 18″ height on a 10″ wide base is within a 2:1 height to base ratio (1.8:1) - I don’t think the triple-stack will be unstable, but nothing wrong with just going a little more conservative either. I see a lot of cribbing solutions are built with a square footprint (would be 16″ x 16″ to match length on these). Negligible material difference, and just a little floor space cost around and under the vehicle. You could even hug the inside with the tire to maintain space
*Note, I’m not an engineer, and I’m not selling these. Use your own judgment and use this design at your own risk!
If you’ve got an interesting problem to solve, I’m available for hire - let’s talk!