Grouting & Lining
When properly designed and constructed, cured-in-place-pipe (CIPP) liners will stabilize the structural integrity of deteriorating pipes. But even properly installed liners will not stop existing infiltration in sewer mainlines and laterals.
Tests have shown that after liners are installed, infiltration from joints and cracks eventually re-enters the system at lateral connection reinstatements, connections to manholes, and defects or pinholes in the liner. This allows infiltration flowing through the annular space between the host pipe and liner to re-enter the system.
Many contractors injection grout leaking joints or defects prior to lining in order to prevent resin wash-out or bubbles in the liner which may compromise the integrity of the liner. Using a water-thin injection grout such as AV-100® Chemical Grout via remote packer will permanently seal the annular space between host pipe and liner as well as seal the lateral connection and stabilize the soil outside the lateral connection.
The same applies for below-grade structures such as manholes. Most linings and coatings cannot be applied to wet surfaces, therefore injection grouts are used to stop the infiltration prior to coating or lining the surface.