Garage Slab Question

hslogger · Jul 28, 2020

I jacked up a garage about ten years ago. It was on a single slab, no footers , no metal. Previous idiots hauled the structure in and basically set it down on a giant sidewalk. We demolished it and went new instead of pouring over the crapper that existed. The best way to go. We layed rebar and plastic.
You have your set up leveled. With out question, put down plastic and then metal mesh or rebar. I don't see any footers in your picture, and this looks like a big mono. I wish you luck in the long run.

HawkinsHollow · Jul 30, 2020

Thank you all for your responses. I ended up using vapor barrier, I had it so why not. Overall the pour went well. Quite a bit of work, and it is not perfect but I am very happy with the outcome, and I saved a load of dough by doing it myself. 10 yard pour with fiber, one little low spot, not a pristine finish but I am happy with it. Had one bulge in the form, but thats about it. I think it'll be fine. Only time will tell I reckon.
Here are a few pics

Egon · Jul 31, 2020

Good job.

HawkinsHollow · Jul 31, 2020

CoyPatton said:
You should be worried about condensation! Use a vapor barrier!
I have a major concern about the base for your slab however. Asphalt is typically not put down on a solid base in most residential areas. I fear your asphalt base with develop sink spots and then your concrete slab will not have support and will follow the sink.
Just my opinion, but we have all seen asphalt roads that have been there for decades develop sink spots follow a wet season or a freeze/thaw cycle.

The base has been there for 50 years, asphalt for at least 20 or 30. In my opinion it is stable, it has done all of the sinking it is going to do. I was worried about the concrete truck with 10 yards of concrete driving on my driveway (all the same age). However, I did not notice any deflection while it was sitting there, nor have I noticed any damage after. I think the existing pad will be more than suitable for this application. It for a shop not a road. And we have very little of a freeze/thaw cycle around these parts.