Floor question

I am a newbie and I built the 12x16 shed which is described in the Sobon timber frame book, just like many others have done.I am going to use the shed as my blacksmithing shop. I like a dirt floor in my shop and filled in the space between the 4x8 floor joists with sand screenings. The roof is on so this should stay dry, but my neighbor warned me that the floor joist would rot if covered in this manner. Is this something I need to change? I sure dont want to have to dig out several yards of sand?I am on a ridge and drainage is good?
Thanks,
Bob

So long as wood stays dry...
You could always dig down periodically and check the wood's moisture to make sure it's below 20%, the magic cutoff for where fungus will not tread.

Gutters with a downspout that goes a good distance from the sills could also help.

And heck, if you want to go overboard, dig a drain around the shed in the standard way:
filter fabric, 4" or thereabouts drainrock, and drainpipe draining downslope. Even that would be easier than digging out the sand.

To ease your mind: if the sand or earth touching the sill and joists is below 20% nothing will rot. I live in a rainforest and I found spruce shiplap under our cabin sitting on old forest duff. Ten feet away it's rained 80-100 inches for the last 70 years.

Enjoy your floor.

Zach

Zach,
Thanks,
Bob