UP injection, also known as urethane pressure injection or polyurethane injection, is a method used for the treatment of water leaks in structures. It involves the injection of a polyurethane foam into the cracks or voids in the structure, which expands to fill the space and create a watertight seal.

The UP injection process begins with identifying the location of the water leak and drilling holes into the affected area. The holes are typically spaced about 12 inches apart and are drilled at an angle to intersect the crack or void. A packer is then inserted into each hole and inflated to create a seal.

Once the packers are in place, a liquid polyurethane foam is injected into the voids through the packers. The foam expands to fill the voids and cracks and forms a watertight seal. The foam also cures quickly, typically within a few minutes, so the packers can be removed and the holes filled with a cementitious material.

UP injection is a popular and effective method for treating water leaks in structures, including basements, foundations, and concrete structures. It is a relatively simple process that can be completed quickly and is generally less expensive than other waterproofing methods. However, it is important to note that UP injection is not suitable for all types of water leaks and should only be performed by a trained professional.