#4 Stone (Crushed Granite Ballast) walkway Pro courts use oyster flour

Pro courts use oyster flour or specialty surfaces

used as the main fill in dry creek beds

single-tone alternative on the same project

The ½" is smaller and more comfortable to walk on

#4 Stone (Crushed Granite Ballast) walkway Pro courts use oyster flour#4 Stone (Crushed Granite Ballast) Large Clean Stone for Heavy Drainage & Deep Backfill #4 Stone is the bigger cousin spec stone 1" top size, clean of fines, angular crushed granite. The size drainage engineers reach for when #57 isn't big enough: deep foundation backfill, large culvert bedding, rail grade ballast, and the transition layer between rip rap and finer drainage stone. Meets AASHTO M43 No. 4 ASTM D448 No. 4. If the spec says "4 stone,"