Ballast with building sand

Hi lads

I have run out of ballast with stone not very good but used it as first layer. I have loads of building sand left, can I mix the building sand with stone mix I can break up from mishaped stone and use that as my final layer? can I use building sand as oppose to sharp sand for the ballast mix?
thanks

 

Building sand will be softer. What exactly are you doing?

 

Its for a concrete slab for a 8x8 small room

 

I would probably get some sharp sand as it's for a room. I've mixed in some building sand in the past for concrete at home for stuff that wasn't so important, but did notice that the concrete was a bit softer.

 

OK mate good to know will get sharp.