base for concrete slab floor, and thickness of floor

[woodnimf]

i recently purchased a barn used for horses. the "floor" seems to be a layer of pretty large sized gravel with a layer of sand over it. i would like to pour a cement floor. my questions: can i pour a cement slab directly onto the gravel/sand? and what thickness would be appropriate for a floor used for general purposes, a painting studio? and....just to be safe, is there any problem seeing how the sand had previously been used as a horses latrine?!!
thanks, kim

 

[ishvaaag]

Well microbes use to be quite resistant. Other than that I would advice to thoroughly spread lime all over, even repetaedly letting the mix enter the soil to kill most of what there remaining. Taking it to a disposal facilty for some depth wouldn't be bad either. Then on the replacement or worked thing compact with small roller just looking not to damage your barn. Now you can set your slab on the ground, and I would do, external pavements as well with akin treatments, on some duplicated linings of polyetilene or something so; or even asphalt membrane (as long as you let some free joints to barn). I myself would set a preparation leveling layer and wouldn't do the actual slab to be laid atop it less than 6 inches deep, and would reinforce it.