May 23, 2012 · Why on earth would you wait and drill, when you can set the proper anchors right into the wet cement? I Foundation for garden shed (ground, new, keep, big) - Trees, Grass, Lawn, Flowers, Irrigation, Landscaping... Ashman Black Ground Anchor 15 Inches in Length and 10MM Thick in Diameter, Ideal for Securing Animals, Tents, Canopies, Sheds, Car Ports, Swing Sets (Ground Anchor Drill 8 Pack) 4.4 out of 5 stars 49 CDN$ 178.76CDN$178.76 How to Anchor A Shed Floor. Typically most wooden shed floors need and should have some sort of anchoring. If not, they stand a better chance of being moved by heavy winds. With your holes dug, drop your 4x4 posts in the ground. They should be pretty close to the skids they will be supporting.