RESIN INJECTION UNDERPINNING. Springfield Lakes, Subsidence, Wall Cracks, Structural Engineer Report. This waffle-pod slab has gradual subsidence at the front, causing cracks and gaps that are getting larger and larger. The owner wants to stabilize the slab then start re-painting. Our thorough Structural Engineer Report found that in this case, the ground conditions were Suitable for the Use of Polyurethane Resin Deep & Shallow Injection to densify the founding soils and re-support the front of the house slab. Considering Underpinning? Contact us for an independent opinion before signing any contract for Conventional, Screw Pier or Resin Underpinning.. We are on your side and we are not trying to sell you anything.