Remove all obstructions in way of repair area (existing decking, asphalt, fencing) and dig down to footings by hand around perimeter of existing basement entrance. Shore all interior joist work within repair area with telescopic shoring. Once structure is secure, remove all existing basement entrance footings, walls and concrete staircase and dispose. Once prepared, remove areas of damaged foundation walls and dispose in sections.
Rebuild damaged foundation walls with 10″ cinderblock and blok-lok rebar. Reconnect new blockwork to existing sill plates and let cure. Once fresh blockwork construction is complete, parge block walls with S-type masonry and waterproof with AB-720-38 rubberized membrane. Fasten drainage board to new block walls and install a 4″ weeping tile system with filter cloth around perimeter of new footings. Connect fresh weeping tile system into existing system. On interior of basement, break concrete 18″ back from foundation walls around the complete perimeter of interior waterproofing repair area.
Dig down to footings and remove debris. Fasten drainage board to foundation walls using concrete anchors and install a fresh 4″ perforated weeping tile system with filter cloth in trench. Break open floor and excavate sump basin at a dimension of approximately 2.5ft x 2.5ft x 3ft. Line perimeter of basin with filter cloth and drill 1/2” holes around complete perimeter of basin. Install basin and surround with 3/4“ clear gravel. Install a 1/3hp oil cooled sump pump and connect pump exhaust line. Connect fresh weeping tile system into new sump basin and cover weeping tile with 3/4″ gravel. Reinstall interior concrete floor and backfill fresh exterior foundation walls (including extra soil for previous basement entrance footprint).
