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Home inspector noticed that this floor beam doesn’t have proper column supports. This is part of an addition and it looks like the builder put scrap wood in as makeshift columns. Is this as simple as replacing the scrap wood with proper columns, or is this something that is likely more complex and will require an engineer? enter image description here enter image description here

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    If proper footings were put in place, then just a simple change to 4x4s. No footings/just the slab floor, then engineer time.
    – crip659
    Commented Feb 8 at 18:00
  • You’re referring to underneath each support?
    – Rob
    Commented Feb 8 at 18:04
  • Yes. The posts need more support than what a 4 inch slab usually provides. If it was done right, telling if a footing is there might be hard by eye alone.
    – crip659
    Commented Feb 8 at 18:42
  • Are you asking about the columns, or column supports (footings)? The post itself looks inadequate.
    – isherwood
    Commented Feb 8 at 19:23

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That area looks outside the home's thermal envelope, in which case there should be footings below the frost line. If you have a shallow frost line such that a slab on grade or mat foundation at grade could be adequate, then an engineer might be able to look, bless a slightly tweaked update, and you're back to the finer things in life. As a quick check, you could use a rotary hammer to poke a hole next to the post's base to determine if the concrete there is thicker than 6". Thinner than 6" implies that there's no footing (I would take 4.5" and thinner as proof of no footing, but conclude "I don't know" if I sampled a thickness between 4.5" and 6").

If there's no load bearing wall sitting on top of that beam (and no hot tub, pet elephant, etc.), then your floor probably has the 10 psf dead load plus 40 psf live load of a deck under the IRC (the 10 psf is predicated on your exact flooring--a topping slab of lightweight concrete, for instance, would require a bigger number). IRC R507.3 will provide you with adequate footings. IRC R507.4 will provide you with adequate post sizes. Estimating from your plan view, your post tributary areas would be about 75 ft2 ([(25ft)/3]×[(18ft)/2]).

If you're in a frosty area, then I would want to enlist a geotechnical specialist, where he might conclude that your situation is not susceptible to frost heave and bless the current setup (with proper post anchorages and beam fastenings). Assuming no frost heave issues (and no expansive soil issues), the worst case scenario would be casting a spread footing on top of the existing slab.

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