Helical screw piles (a.k.a. screw piles) replace concrete footings for decks, additions, etc. They can be installed in any weather, with minimal disturbance to the surrounding landscape. Apollo Engineered Helical Screw Piles are CWB certified and stamped engineered drawings are available for permit applications. Screw piles are accepted as deep foundation units: Alberta Building Code A-4.2.7.1., National Building Code A-4.2.7.1. Design loads are based on a soil composition of Stiff Clay with Undrained Shear Strength of 90 KPa.