Is it normal for a deck to be resting on stacked concrete blocks?

Those stacked concrete blocks are a major red flag and almost certainly won't pass a strict building inspection. While CMU blocks are strong in compression, they aren’t meant to be used as loose, unmortared piers for a residential deck. The main issue is lateral stability; there is nothing actually tying that deck to the ground. If the house settles or the soil shifts, those blocks can tilt or slide, and the whole beam coud slip right off the top. Most building codes require a continuous load path from the joists to the beam, then down trough a **mechanical connection**—like a post base—into a concrete footing that extends below the frost line. Sitting a beam directly on a pile of blocks is a shortcut that skips the necessary hardware. Even if the blocks are sitting on actual footers, the lack of a secured post means the deck is basicly just floating on a stack of heavy bricks.

It's a common DIY fix because it's cheap and doesn't require digging deep holes, but it’s definitely not standard practice for a deck of any significant size. If you’re planning on having a crowd over or putting anything heavy like a large grill out there, you’re asking for trouble. The structure depends almost entirely on gravity and friction to stay in place, wich isn't a real safety strategy. But this is usally fixable without tearing the whole deck down. You can often use heavy-duty jacks to temporarily support the joists, knock out those block towers, and install proper **6x6 pressure-treated posts** on the existing footers. You'll need to use the right brackets to bolt the posts to the concrete and the beam to the posts. It’s a few days of sweaty work and some lumber costs, but it’ll give you the peace of mind you’re looking for before that inspector shows up.

I'm totally new to this, so excuse the basic question, but how do you actualy jack up a deck to swap those blocks out? Is that somthing a regular person can do with a car jack, or do you need special heavy-duty equipment? I'm also wondering if you have to dig new holes if those blocks were just sitting on the surface. If the ground is soft, do you have to pour a whole concrete base first? I don't know much about building yet, but trying to figure out how much work this realy is.

Forget the car jack unless you want a trip to the ER. Grab a 12-ton bottle jack and some 4x4 scrap to spread the load across the joists. The real killer here is the frost line. If those blocks are just sitting on topsoil, they’ll heave and sink every winter. You need to auger out holes for 12-inch Sonotubes—ussually 36 to 48 inches deep depending on where you live. Set some Simpson Strong-Tie ABA66Z bases in the wet concrete so your 6x6 posts aren't soaking up ground moisture. It’s a weekend of work, but it beats watching your beam roll off a stack of CMU blocks during a party.

Since you're looking at a big repair anyway, skip the bags of concrete and look into Diamond Pier DP-50 foundations. I switched to these after a DIY nightmare with a manual auger. You just set the concrete head on the ground and drive those steel pins in with a demo hammer. It’s way faster than pouring traditional footings and they’re rated for frost. It saved me so much back pain and the inspector loved seeing a branded, engineered system instead of some mystery blocks.