Terrace Waterproofing in Velachery, Chennai

Why Velachery terraces leak

Velachery is low-lying and sits close to the Pallikaranai marshland and Velachery lake, and it takes heavy rain during the north-east monsoon. When storm drains back up, water drains off terraces more slowly, so a roof with a weak surface, a poor slope or blocked outlets can have water standing on it for hours.

Standing water finds every crack. Long summers also take their toll: terraces heat up and cool down every day, and over the years the surface cracks and old coatings break down. The first heavy rain of the season is usually when it shows up as a ceiling leak.

How we assess a leaking terrace

Before recommending anything, we check:

• The slope of the terrace and whether water reaches the drain outlets
• The condition of outlets, rainwater pipes and the joints around them
• Cracks in the surface, the old coating or the tiles
• The parapet junction, expansion joints and pipe or cable entries
• The ceiling below, to match where water appears with where it may be getting in

Terrace waterproofing options

The right system depends on the condition of the terrace and how it's used. Options include crack treatment with a liquid-applied waterproof coating, polymer-modified cementitious coatings, PU or torch-applied membranes, and, where heat is also a concern, reflective cool-roof coatings. If tiles are trapping water, they may need to come off so the slab can be treated properly.

Most terrace systems need a dry surface to bond. During the monsoon we can often stop an active ceiling leak first, for example with injection grouting through the crack, and plan the full terrace treatment for a dry spell.