Case Study: Basement Waterproofing in Hebbal, Bangalore

The Problem

A 24-unit apartment in Hebbal's lake-adjacent zone had 6-8 inches of water in the basement parking every monsoon season for 4 years. Residents' vehicles were being damaged. Previous treatment attempts — two surface-applied polymer coatings — had failed completely. The RWA was considering legal action against the builder.

Our Diagnosis

Structural water ingress from hydrostatic pressure. Hebbal's proximity to Hebbal Lake means groundwater levels rise to within 1-2 metres of the surface during peak monsoon. The water was entering through construction joints (where separate concrete pours meet) and through hairline cracks in the basement walls and floor slab. Surface coatings cannot resist hydrostatic pressure — water pressure pushes through any coating applied from the inside.

The Solution

PU injection grouting into all visible cracks and construction joints (45 linear metres total) — PU foam expands to fill and seal the crack from inside. Sika Crystalline applied to full basement floor and walls (active ingredient migrates into the concrete and crystallises within voids and capillaries permanently). Fosroc Conplast WP admixture added to repair mortar for all surface patching. External drain channel installed at basement perimeter to manage any residual surface water.

The Result

What This Job Cost — And Why

The total cost of ₹1,85,000 for this job breaks down as: 35–40% materials, 25–30% surface preparation and labour, 10–15% mobilisation and equipment. This is higher than the cheapest quotes the customer received — but it produced a permanent fix where two previous cheaper jobs had failed completely.

The framework for evaluating any waterproofing quote isn't price per sqft. It's: What is the contractor's diagnosis of the root cause? What preparation will they do? What material and how many coats? What does the written warranty cover? Get those four answers in writing before comparing quotes.