Garage Slab / Floor replacement options

[GarageNovice]

Hello!

I’m hoping for some suggestions. Our neighbor’s construction/excavation undermined a decade old, detached, single car garage (lightly used). W/o getting to detailed, basically excavation poorly done up to edge of our garage 20 feet deep created void beneath portion of garage. Solution was for them to build retaining wall up to the side of garage at property line closest to void, and fill void from above (ie through garage floor) with concrete mix/settling technique. Overseen by city and engineers. Anyway, from what we understand from professionals, the garage itself was not damaged (still investigating some aspects), but the garage floor certainly was - first from the void created, which caused wall to wall cracking, and then from solution (drilling holes to access void to fill). Now the question is what am I asking for? They have agreed to fix/remedy but I want to make sure what I ask for is both feasible and smart, thinking about the ascetic and the future stability/life of whatever we do. I don’t have a construction background nor do I know the various options associated with garage floor replacement, so I’m ears wide open. Thank you in advance!

 

[kd3pc]

the caliber of this repair, given what has happened, pushes you in to the "engineer" needed. Someone to stand up for your interests. The garage/floor will be around for some time, after this debacle is settled.

Others will offer their ideas, but without concrete and engineer findings and reports, pictures, etc - all speculation

 

[ConCretin]

It sounds like your neighbor is responding appropriately and there is some professional oversight involved but I agree with kd3pc about the need to protect yourself. If you are not comfortable that those involved are protecting your interests not just those of the neighbor or the city, I’d request a third party engineering review on their dime.

With regard to your floor slab, I’d be looking for removal and replacement of the slab and base. The existing slab is apparently cracked and full of test holes, which uncovered voids below. There is no repairing all that. It’s probably even cheaper to rip it out and replace it. Good luck.