1

I have an old barn/garage that has mason block walls. The entire foundation is a concrete slab with footings for the exterior walls. For some reason, about 6 inches from the exterior walls, the concrete is cracked, and is sticking upwards.

Why is this happening and is it something I need to worry about?

I plan to frame a wall across this, however, the crack makes the flooring uneven, so how do I even out the floor?

enter image description here

1 Answer 1

3

That crack looks too uniform (straight) to be a structural crack.

The concrete under the masonry wall is probably the top of the foundation wall. I suspect the slab was poured up against the foundation wall and the edges of the slab have spalled off.

If you notice there’s a control joint running perpendicular to the masonry wall too. This helps keep the slab from having random cracks.

Yes, the joints are a little rough. You can grind down the high spots and fill in the low spots with a concrete filler or sealant if you’re concerned about expansion. (Concrete continues shrinking as it ages, unless you live where the sun could heat the slab and make it expand.)

2
  • Thanks for the response! So it'd probably be safe to grind down the high spots and place a wall right over this crack? Jul 14, 2020 at 16:06
  • @GaryHoliday Yes, and it’s not structural so you don’t need to bolt it down...just use concrete nails.
    – Lee Sam
    Jul 15, 2020 at 0:48

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.