Garage repour

[APG12]

I have a ~40 year old slab that is in pretty rough shape and was apparently poured with no base material at all. I’m getting ready to start pricing out a repour. I’m planning to demo the floor myself and then have to pros come in to pour the new slab.

Before is start getting estimates, what should I be looking for in my quotes? Base material/thickness, vapor barrier, etc... Any help would be appreciated.

 

[rustyjames]

Definitely vapor barrier, it's not a lot of money to the cost.

 

[ConCretin]

You seem to feel that your existing slab failed due to a lack of base material. I'm curious why you've come to this conclusion. Has the existing slab heaved and settled? The need for and composition of a base layer over native soils depends on the nature of those soils.

If the native soils are sound and stable, there isn't any requirement to remove them and add a layer of a different material. All the slab needs is uniform support. If you find the soils under your slab are unstable, wet, expansive or otherwise unsuitable, you will have to address the issue.

If you've got s few minutes, give my Guide to Floor Slabs below a read for some additional thoughts.

 

[APG12]

You seem to feel that your existing slab failed due to a lack of base material. I'm curious why you've come to this conclusion. Has the existing slab heaved and settled? The need for and composition of a base layer over native soils depends on the nature of those soils.

If the native soils are sound and stable, there isn't any requirement to remove them and add a layer of a different material. All the slab needs is uniform support. If you find the soils under your slab are unstable, wet, expansive or otherwise unsuitable, you will have to address the issue.

If you've got s few minutes, give my Guide to Floor Slabs below a read for some additional thoughts.

There are several areas that have settled and cracked. I had to trench a run across both bays to repair a water line and discovered no base material. The slab also thins out on on half of the garage. I will definitely give your guide a read, thanks. Just want to make sure it’s done right.

 

[Slowgsr]

My house garage had 6" voids under it from settlement. They never compacted the backfill around the foundation edges, just put the regular fill back.

The demo& prep is the most work. I use my mini ex, broke up the floor, loaded my dump trailer, adjusted the subgrade and compacted, 2" of foam, poly, and tied rebar. Then me and my brother in law did the pour. I had minor dusting of my finished slab from over working the surface, but after full cure, cleaning and epoxy it turned out great.