These lift pits
flooded with approximately 2ft of water, causing problems with the lift
mechanism and maintenance.
pneumatic and electric pumps are used to pressure grout with various
resins including water reactive polyurethane and chemical reacting
Some of these
resins react with the leaking water at depth within the structure and
actually ‘consume’ the water in a chemical reaction and turn it into
part of the waterproof material deep within the cracks and voids.
high-pressure injection lance or non-return injection valves are used at
the entry point into the structure.
‘tanking’ system is applied over the entire area as a secondary means
of waterproofing. In this case a polymer modified cement based thin
section render was used. Note that this kind of system would only be used
where the structure was sufficiently rigid and strong and where means of
eliminating water pressure have been implemented. Relying on the tanking
material alone would be a high risk strategy.
study has been submitted by a member and the British Structural
Waterproofing Association accepts no responsibility for its content.