New floor

[Reg1952]

My garage floor 13 x 35 is coming out because it has no drain and is cracked and sloped badly in all the wrong places. I want to raise is up about 4'' as well to allow for a new driveway that can be sloped away from the garage door. During heavy rains water run to my garage. I have a few questions. First is, 4 or 5 inch thick? Then steel or no steel?. Fiberglass instead? Vapour barrier under the new pour? Thanks

 

[RPH]

5" as it only helps, rebar yes, plastic most definitely. Fibers are not really structural but do help with the fine cracks, your call on that.

 

[lakeroadster]

Form follows function.

What is the intended use for this space? Simply car storage? Will you ever install a lift?

The more you tell us, the better the answer you will get.

 

[Reg1952]

Just to park a car on.

 

[spudley]

4" is fine.

 

[lakeroadster]

Just to park a car on.

I would go with:

Good compaction of the sub grade, this is the most critical key to slab longevity,

Wire mesh sheets for reinforcement, supported by concrete dobies,

4" thick 3000 psi concrete with fiber mesh,

Control joints cut within 8 hours of finishing the concrete,

Control joints filled with Sika Flex, or equal, wherever water will eventually be (wet cars, etc.)

Poly? Your call. Talk with your contractor about that.