cracked concrete floors-whatado?

[Dale R. Hamilton]

The 4" concrete slab poured as my shop floor has cracked badly. Maybe it was the 19,000 lb Mack truck I backed in there. Anyway, if it were a few hairline cracks I could live with them- but the cracked sections have lifted some 1/2" above grade- to the point where people trip on them. Any ideas- short of breaking up the floor and atarting again? oh Yeah, this is about 1200 sq ft.

[Alan D. Hyde]

Lay 2 x 6's, flat on their sides, on 16" centers over the existing floor, then plank or board over it (depending on the uses to which it will be put).

Easier on tools and legs.

Less trouble to fasten to, and won't subtract much from the overhead of the work space.

Alan

[ 10-09-2002, 12:28 PM: Message edited by: Alan D. Hyde ]

[Dale R. Hamilton]

God- thats alot of 2x6's and planking- and then I'd be 7 or so inches above the drive way. Maybe another solution?

[Alan D. Hyde]

Dale, a flat 2 x 6 is 1 1/2" thick. If you plank over it, that's another 1 1/2".

That makes a total of 3", or of 2 1/4" if you use boards instead of planks.

Alan

P.S. Cost via a local WoodMizer guy (see those threads) will be about 10 cents per board foot. For 1200 sq. ft. we're talking around what? $300-400??

[ 10-09-2002, 12:32 PM: Message edited by: Alan D. Hyde ]

[John of Phoenix]

Just had the same problem fixed in our living room. :eek: and did the same as rkrough but leveled back about four feet. Worked fine.

[TomRobb]

Depends on your goal. Smooth or flat? If it's flat you're after dig it out, put down a nice well drained compacted gravel base and new concrete with maybe 10x10 wire reinforcement over a plastic film vapor barrier and park the Mack elsewhere :D

[Dale R. Hamilton]

been thinking there must be some way like rich describes- I like it, thanks guys.

[ken mcclure]

Just be sure that the problem that's causing the slab pieces to shift has been fixed. If not, any patch you put on top will also shift and crack again.

The most permanent fix is the one above that involves digging and re-pouring. Not as bad as it sounds ... rent a concrete saw, cut out the bad center portion. Drill holes around the edge and insert short pieces of rebar. Tie rebar and/or mesh to those pieces and pour a new slab section.

[SailBoatDude]

I watched a show on one of those fix-it upper type channels about lifting up slabs that had sunk due the ground going away under the concrete for whatever reason. They pumped in concrete (hydraulic, I think) across the lowered area through holes drilled in a radiating pattern moving towards the lowest point. Damn'd if it didn't raise up before your eyes. Thought it a rather clever use of this type of concrete and will try it someday maybe. Try a search on the Discovery Channel.

You could paint the cracks bright yellow and display signs about the tripping hazards . . . a bit cheaper, but not a fix

[WFK]

Unless you're really set on having the concrete, I like Alans Idea, except I think I'd use 3/4 or even 1" plywood. It would be very solid.

Bill

[Paul Scheuer]

I think Bob Villa showed in once. It seemed like slab floated on the new material. I suppose wet concrete is more dense that curred stuff. Here in the Midwest, they do a lot of mechanical jacking and filling. The key, as said above, is to understand and fix the cause. Here it's mostly frost heaving and settling in new construction.