Sand,not to sure if this matters?

[catch22]

I am in the process of getting ready to put my concrete in my pole barn addition,but I have about 22 inches of fill I need to put in.Im thinking about putting 12 inches of sand and 10 inches of gravel on top of the sand.My question is does it matter if the sand has some stones in it.The cost of screen sand is about $10.50 a ton and $4.50 for the sand with stones does this really matter since im putting gravel over top of the sand?Any advice would be greatly appreciated.

Thanks Mike

 

[kbs2244]

The way you are discribing it, a little gravel will not matter.
But my question is why the sand?
If there is any danger of water around your building, sand will wash away before gravel.
I would go with crushed gravel with it's "fines" still in it.
That stuff will pack down to almost concrete hardness.

 

[ddawg16]

Typically it's the other way around....I thought...gravel first and then sand....

Check you local building codes....even if you are not doing it to code, they are very good guidlines to follow.

 

[catch22]

The guy behind me just poured his pad and they put down sand first then gravel and his is an engineered pad for his garage.
The reason I was going to even use sand was that I thought it would be cheaper and easier for the fill,than it would be to put all gravel.But maybe I should be reconsidering and just go with all gravel.

Thanks Mike

 

[jamm]

Don't forget to compact your fill in lifts.

 

[catch22]

Sorry,but what do you mean by compact my fill in lifts?

 

[jamm]

Sorry,but what do you mean by compact my fill in lifts?

You stated that you needed 22" of fill in your original post. Industry standard is to run a compactor after each 12" layer of fill is placed. When compacted properly, this will make sure that there is no settling of the fill material once the floor is poured therfore your slab will have proper support. You can rent a walk-behind compactor at most equipment rental stores.

 

[rodnok1]

I thought you should compact every 4-6 inches, esp whith a plate compactor

 

[Bigger Hammer]

I thought you should compact every 4-6 inches, esp whith a plate compactor

I agree, 4-6 is ideal and 8 would be the absolute max I'd even consider. If you have a large heavy vibratory smooth drum roller or sheep's foot you could do 12 inch lifts.

And to the original post. I wouldn't mess with two types of fill material unless I was going to use clean fill dirt and top it off with about 8 inches of stone/gravel. But the dirt needs the compaction in lifts just like the stone would, and a plate compactor will not work with the dirt fill. If you do go with the sand, the dirty sand will not make a difference.

 

[catch22]

Thanks alot for all of your replys,I really do appreciate it.

Thanks Mike