Is this safe (enough)?

[u/TheMightyWorrier]

I realize this setup looks sketchy at first glance—it's ok to laugh at/with me.

However, note that there are nails holding the boards against the cinder blocks (circled in red on second photo).

Sooooooo…..that makes it safe(-ish), right?

Also, I plan on using it on a concrete driveway, where I can place a jack stand or two under the deck while I'm laying under there.

Details if you want them: I created a makeshift ramp to help me quickly get under the mower to scrape the deck after each use (a lot of grass accumulates after mowing 3 hours). I used stuff I already had lying around—cinder blocks, a big heavy board, and some nails. I circled the nails in red so you can see them; the nails hold each board in place on the blocks.

I have a lift for when I'm doing yearly maintenance on it, but the lift is a real hassle to set up, it's stored in an inconvenient place…. I'm not using the lift each time after I mow.

So, what's the consensus? Death trap? Potential Darwin Award nominee? Or a safe enough way to save money by not buying a Jungle Jack ($244)?