new concrete floor question

[Wild Turkey]

New house basement storage area -- LOML says she wants shelves along back wall for plastic tubs to store "stuff" in.

So I'll build some 2x4 and CDX shelves but I'm wondering about the bottom row.  I'll keep the 2x4's a couple of inches above the floor but I'm concerned about trapping moisture under them and having problems in the future.

How long should I let it cure before sealing/painting it? Would a little more space make things better?  (the storage area will have air circulation -- she hates musty basements like her parents had


Would slats be a better idea to allow air circulation?

[fredhargis]

If you allow a couple of inches you're golden. that's all you need.

[Stwood_]

Concrete cures in 28 days. Always has, probably always will.

I would keep the 2x's off the floor for air circulation.

[Turner52]

You could also set the bottom right on the concrete, but do it out of slats spaced as far apart as possible and still be in the proper placeing for the tubs to sit on, no need for an actual shelf top. Concrete will do all of the support. This would also allow for circulation

[EightFingers]

I thought it took about 90 years for concrete to “fully” cure....

[Turner52]

Concrete reaches full hardness in 28 days. It can continue to give off it's own moisture for much longer. It can also allow moisture from the ground to permeate thru forever.

[ajkoontz]

How long should I let it cure before sealing/painting it?

It depends on what product you are using. For example, there are curing/ sealing products that can be applied right away. Something like paint you should wait longer. 28 days is the rule of thumb, but concrete cures forever. It's just that after 28 days the rate is so slow that it is usually negligible.

[Mr_Mike]

I'd not use a bottom shelf. Kind of a useless use of material. Just use plastic bins or whatever directly on the floor.