Tony, I need 4 tonne of bedding sand, I currently have 2 1/2 tonne of sharp sand, would you advise me to get another 1 1/2 tonne of sharp or 1 1/2 tonne of ballast to mix in with the sharp
More sharp sand. "Ballast" is a loose term that can include almost anything and you could end up with some chunky rubbish that's difficult or even impossible to screed. :(