If you see a leak or brown stain appear on the ceiling inside your home and have a terrace above that ceiling, the terrace may be leaking. Because many terraces are made of concrete and are exposed to the weather constantly, cracks or holes may form. When this occurs in a terrace, water will begin to seep through the concrete pores and downward into the living space.
Clean out the crack or hole in the terrace by combining one part TSP with three to four parts water in a bucket. Scrub the hole or crack with the mixture and a scrub brush then rinse the crack or hole with a bucket of water.
Combine three parts fine sand with one part hydraulic cement in the bucket. Mix it together with a trowel then add water until the mixture is moist but not runny.
Squeeze concrete bonding agent into the crack or hole in the terrace then apply the cement mixture from the bucket with a trowel. Spread the wet cement mixture over the hole or crack in the terrace, making it smooth and even. Allow it to dry for 24 hours.
Apply a coat of masonry and brick sealant over the dried cement patch on the terrace with a paintbrush. Let the sealant dry for 24 hours to finish the terrace leak repair.