Engineered suspended garage slab

[Gene Davis]

Cars drip water and here they drip tons of slush, so waterproofing is as big a deal, construction-wise, as the floor structure itself.

Autos, light trucks, and SUVs don't require as much structure as you might think, but certainly some engineering is involved. If you can stand a post or two, and a dropped beam, in your space below the two-stall garage, you'll need less structure.

Some use prestressed hollowcore concrete planks and run full span. In many cases, 10" plank depth will do. Such a floor gets topped with a thin concrete slab. Others use something like LiteDeck forms to do a reinforced concrete full span deck. Alternatively, one can do it with structural steel, corrugated steel deckform, and reinforced concrete slab atop.

In all cases, one must design for drainage by pitching the slab, etc.

Then there is insulation to deal with, unless you are in a place like maybe Hawaii where it is wondrously temperate year round. The LiteDeck forms solution is a good one for insulation.

[Tundara Homes]

The LiteDeck forms solution is a good one for insulation.

I do like this idea. I have been looking into quad deck, a similar product, but this site has much more info. They actually show spans. Thanks Gene.