The injection of polyurethane (or silicate, epoxy) based resins using high pressure pneumatic pumps and packers, into gaps and cracks in the structures. The mixture then reacts and in turn expands and toughens, stopping water flowing through these structural joints and cracks. Best used in waterproofing and stabilization purposes structures such as tunnels, subways and dams. The Packers are placed in drilled holes drilled at slanted degrees to intersect the interior around the cracks and gaps allow the resin to infiltrate deep into the most inaccessible areas. Our single or double chamber high pressure pneumatic pumps are designed for easy maintenance, highly reliable and very easy to use.