PU Injection Grouting technology is an apt methodology for treating leakages.
While treatments at source or on positive side are popular for their lower costs and precision. Negative or affected area injection grouting is the modern, advance technology for arresting leakages especially if the source of the leakage is inaccessible or hard to trace.
The use of polyurethane is advisable due to its capacity of expanding (on foaming) which helps arrest the leakage along the passage way especially if the leakage is profuse. Expanding foam completely fills the cracks and prevents future water leaks.
Reverse PU injection should be carried out with proper understanding of the built-form and material . The process should be carried out by skilled personnel only or you can appoint an expert waterproofing contractor in Mumbai.
Do watch our you tube video Part-1 and 2
While theories thrive around the effectiveness of PU injections, it is highly recommended for sub-structures and leakages extending over long duration of time.